Hey everyone, first post on here. I’m building a 1990 K5 blazer right now. 383/700R4, 14B rear/10 Bolt front, everything else is pretty much stock. I want to know what you guys suggest for upgrades/mods for mild over landing on 37s. I’ve heard about 1 ton swaps, and crossover steering but I don’t know a whole lot about the offroad NEEDS so if anyone could give me some suggestions it would be greatly appreciated!
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Blazer upgrade suggestions
- Thread starter Parker D
- Start date
For mild overlanding you probably won’t need 1 tons. I would make sure you have a good gear ratio for you set up (or future plans), you have an overdrive transmission so a little over geared is still reasonable for you. Personally, I’d shoot for at least 4.56 gears but 4.88’s will make it nice and strong.
Great locker will do wonders for the truck’s ability, a front locker is cool but could make steering heavy or difficult.
Crossover steering is always nice but probably a personal preference for your use. I would definitely look in to steering braces, clean & check the frame behind the steering box extra thoroughly (don’t be surprised if you find cracks, this is common) and lastly the Jeep XJ steering shaft mod is a great way to tighten the steering feel.
Great locker will do wonders for the truck’s ability, a front locker is cool but could make steering heavy or difficult.
Crossover steering is always nice but probably a personal preference for your use. I would definitely look in to steering braces, clean & check the frame behind the steering box extra thoroughly (don’t be surprised if you find cracks, this is common) and lastly the Jeep XJ steering shaft mod is a great way to tighten the steering feel.
The only weird position I’m in is whether I put all that money into building a 14b/10b and risk having front end problems at some point, or spend th extra money and build a 14BFF/D60
good quality parts NOT cheep budget parts in front end . some good aftermarket shafts / yukon locking hubs and good spicer life series wheel joints should do you fine . the aftermarket support these days for dana 44 & 10 bolt front is huge and brings the strength way up near a 60 stock would be for your current needs.
14ff dont need hardly anything done there strong .
a 60 front is nice all stock is nice . but its not needed in your needs at this time .
14ff dont need hardly anything done there strong .
a 60 front is nice all stock is nice . but its not needed in your needs at this time .
The overland/mild crawling is right in line with what I do.
Here’s my thoughts based on what you are working with and my experience. Drivetain-wise sounds like a good setup. You didn’t mention if it was carbureted or EFI in your post. I’m going to assume carb since it’s a 383 md stock TBI setups don’t typically work well with modified engines. My point here is if it’s carbureted, look into going to EFI. That would just make life a lot easier when exploring. Altitude compensation is automatic as well as just being easier to start and run more efficiently.
Your existing axle setup is fine for the target you are aiming for. I’m running a d44/14bff combo and even with a 8.1 that has been solid. Though I’m running 35’s and prior to the 8.1 install I had snapped three front shafts with a 5.3LS. There were other factors at play there but in your case I would think about the tire size choice. Mainly since the 37’s are going to make the front shafts be your fuse in the system, even more so if you put some type of traction device up front. Tire size will factor into the suspension too, but I’ll get into that a little later. Gearing with 37’s is going to need to be aggressive like Nvrenuf said and the ratios he mentioned are spot on. If you are re-gearing that’s the time to think about at least one traction device if not two. Really comes down to budget. I’m personally running a Detroit Tru-trac up front and love it with an open diff in the back. I could have used something out back on harder trails but I have not wanted to deal with the road manners of a Detroit locker on the highway.
Suspension is where the tire size choice is going to weigh in heavy. Like I said I’m running 35’s on 4” Skyjacker softrides up front with ORD HD shackles and stock springs out back with an ORD 4” shackle flip. The rear leafs have had a couple of leafs added due to the weight of my K5, but otherwise stock. I’m running Bilstein 5100 shocks all the way around. To be honest with my setup despite my modest tire size the lift still doesn’t allow the front tires to clear the fenders in all situations. I don’t want to go higher so I’ve got some bushwacker cut out flares to give me more room.
To clear 37’s you are going to need more lift and still will need some trimming action to the front fenders. Also as far as K5’s go even at only 4” lift your rear driveshaft is going to need some help as the shaft angles get crappy any way you lift it (springs , blocks or shackle flip). Part of that is due to your 241 transfer case that should be in there. The slip yoke output forces the rear shaft to be shorter and is why as the rear gets lifted the angles go out of whack so quickly. A slip yoke eminator is ideal to get be able to add some length to the driveshaft with a double cardamom set on the front of it. Though I’ve had a shaft built to work with the slip yoke and added a double cardan setup on the front to deal with my horrible shaft angles.
So really if you go 35’s on 4” lift or 37’s on 6” lift either way you are going to have to deal with some crappy shaft angles out back.
Steering you don’t have to move away from stock push/pull setup for crossover unless you want to. The problem comes in that you’ll have more work and cost involved doing it on a 10 bolt. The pass side knuckle on a 10bolt has no provision to mount an arm to it to accept a Drag link. Early d44 passenger side knuckles did, but still require machining to do it. Keep in mind d44’s and 10b front axles have interchangable parts from the knuckles out. Reid may still make a passenger side knuckle ready to go, just haven’t looked lately.
Here’s the issue going crossover for a mild wheeler/overland setup. You will have to remove the stock sway bar setup. For a dedicated wheeler that gets trailered to a trailhead that’s totally fine. For one that’s going to see highway duty primarily and then hit dirt, it’s a whole other ball game. I drove mine with the sway bar disconnected (I have a quick disconnect kit from ORD) when the retaining pin fell out in AZ somewhere and drove all the way back to Denver and it was not a fun drive at all. Hooked back up, drove fine.
The stock steering systems biggest downfall whe the suspension is maxed out articulating. Left side drooped while the pass side is stuffed. That forces the drag link down and effectively reduces the overall length and takes away the leverage. You can turn the wheel but they won’t steer. I’d say in 20+ years of this stuff I’ve experienced that on the trail maybe twice. Each time I backed up, took a different line and got through whatever I was on. Those were on some fairly gnarly trails too. So it hasn’t happened all that frequently for me to push to make the change.
I will say this, whichever way you decide, the steering box brace and frame reinforcement plates from ORD are a mandatory thing for any 4wd squarebody. Dump the stock rag joint and intermediate shaft for the xj unit Nvrenuf recommended too. Between those three things and a fresh not worn out steering box made my steering nice and tight with zero wander at highway speeds.
You probably noticed I mentioned ORD multiple times. Off Road Design is the go to source for parts for our trucks. The company supports this site as well as Blazer Bash in Moab every year. It’s worth checking out their site to see what else they offer.
Here’s my thoughts based on what you are working with and my experience. Drivetain-wise sounds like a good setup. You didn’t mention if it was carbureted or EFI in your post. I’m going to assume carb since it’s a 383 md stock TBI setups don’t typically work well with modified engines. My point here is if it’s carbureted, look into going to EFI. That would just make life a lot easier when exploring. Altitude compensation is automatic as well as just being easier to start and run more efficiently.
Your existing axle setup is fine for the target you are aiming for. I’m running a d44/14bff combo and even with a 8.1 that has been solid. Though I’m running 35’s and prior to the 8.1 install I had snapped three front shafts with a 5.3LS. There were other factors at play there but in your case I would think about the tire size choice. Mainly since the 37’s are going to make the front shafts be your fuse in the system, even more so if you put some type of traction device up front. Tire size will factor into the suspension too, but I’ll get into that a little later. Gearing with 37’s is going to need to be aggressive like Nvrenuf said and the ratios he mentioned are spot on. If you are re-gearing that’s the time to think about at least one traction device if not two. Really comes down to budget. I’m personally running a Detroit Tru-trac up front and love it with an open diff in the back. I could have used something out back on harder trails but I have not wanted to deal with the road manners of a Detroit locker on the highway.
Suspension is where the tire size choice is going to weigh in heavy. Like I said I’m running 35’s on 4” Skyjacker softrides up front with ORD HD shackles and stock springs out back with an ORD 4” shackle flip. The rear leafs have had a couple of leafs added due to the weight of my K5, but otherwise stock. I’m running Bilstein 5100 shocks all the way around. To be honest with my setup despite my modest tire size the lift still doesn’t allow the front tires to clear the fenders in all situations. I don’t want to go higher so I’ve got some bushwacker cut out flares to give me more room.
To clear 37’s you are going to need more lift and still will need some trimming action to the front fenders. Also as far as K5’s go even at only 4” lift your rear driveshaft is going to need some help as the shaft angles get crappy any way you lift it (springs , blocks or shackle flip). Part of that is due to your 241 transfer case that should be in there. The slip yoke output forces the rear shaft to be shorter and is why as the rear gets lifted the angles go out of whack so quickly. A slip yoke eminator is ideal to get be able to add some length to the driveshaft with a double cardamom set on the front of it. Though I’ve had a shaft built to work with the slip yoke and added a double cardan setup on the front to deal with my horrible shaft angles.
So really if you go 35’s on 4” lift or 37’s on 6” lift either way you are going to have to deal with some crappy shaft angles out back.
Steering you don’t have to move away from stock push/pull setup for crossover unless you want to. The problem comes in that you’ll have more work and cost involved doing it on a 10 bolt. The pass side knuckle on a 10bolt has no provision to mount an arm to it to accept a Drag link. Early d44 passenger side knuckles did, but still require machining to do it. Keep in mind d44’s and 10b front axles have interchangable parts from the knuckles out. Reid may still make a passenger side knuckle ready to go, just haven’t looked lately.
Here’s the issue going crossover for a mild wheeler/overland setup. You will have to remove the stock sway bar setup. For a dedicated wheeler that gets trailered to a trailhead that’s totally fine. For one that’s going to see highway duty primarily and then hit dirt, it’s a whole other ball game. I drove mine with the sway bar disconnected (I have a quick disconnect kit from ORD) when the retaining pin fell out in AZ somewhere and drove all the way back to Denver and it was not a fun drive at all. Hooked back up, drove fine.
The stock steering systems biggest downfall whe the suspension is maxed out articulating. Left side drooped while the pass side is stuffed. That forces the drag link down and effectively reduces the overall length and takes away the leverage. You can turn the wheel but they won’t steer. I’d say in 20+ years of this stuff I’ve experienced that on the trail maybe twice. Each time I backed up, took a different line and got through whatever I was on. Those were on some fairly gnarly trails too. So it hasn’t happened all that frequently for me to push to make the change.
I will say this, whichever way you decide, the steering box brace and frame reinforcement plates from ORD are a mandatory thing for any 4wd squarebody. Dump the stock rag joint and intermediate shaft for the xj unit Nvrenuf recommended too. Between those three things and a fresh not worn out steering box made my steering nice and tight with zero wander at highway speeds.
You probably noticed I mentioned ORD multiple times. Off Road Design is the go to source for parts for our trucks. The company supports this site as well as Blazer Bash in Moab every year. It’s worth checking out their site to see what else they offer.
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Hey ZooMad, thanks for the reply, I should’ve specified more about my vehicle, I underestimated how much you guys knew about all this stuff. I bought this truck with a 6” lift already installed and 37s, the previous owner obviously did some mild wheeling considering some of the characteristics(14B rear swap, lift, extended driveshafts, and some other small things). You are correct, it is carb’d, but I plan to do either an LS swap in the near future or a Holley EFI kit to get the creature comforts of fuel injection.
My goal with this build is to essentially be able to get in and take this thing anywhere my heart desires without having to worry if my rig is going to have a catastrophic failure that is going to keep me from making it back home. By “anywhere” I mean anywhere within reason, I’m not gonna try to tackle any crazy trails solo or anything. I live in Kansas so there isn’t anything super close that can really get me into trouble within my knowledge, and for breaking down. I know there never a 100% fool proof rig(especially when beating on them) so I mainly refer to just having a good reliable vehicle that will also be able to tackle trails on weekend trips.
My biggest concern is by the time I’m done building my 10 bolt or a Dana 44. I’d have enough money in it that I could’ve just bought 1 tons and called it a day.
Any suggestions on other build recommendations are also super helpful as I don’t have any experience with wheeling(outside of SxS) and love to learn more about how you guys build these things to perform… thanks again
A D60 in junkyard condition can cost $2000 dollars these days. If you want to spend the money you still have to find one for sale, which is actually pretty difficult. There are options for alloy axle shafts for a D44 now, which still cost $1800 but at least you can order them. A new D60 from spicer, dynatrac or others is $10,000.
I run a D60, AAM10.5 w/ yukon grizzly locker. AAM10.5 is a late model 14FF with factory disc brakes. Its really what you want if you are swapping to a 14FF. You can wheel pretty hard with a D44 in the front if its unlocked and you have a big 14FF locked pushing you over obstacles. I have a big block so I went to the D60.
I run a D60, AAM10.5 w/ yukon grizzly locker. AAM10.5 is a late model 14FF with factory disc brakes. Its really what you want if you are swapping to a 14FF. You can wheel pretty hard with a D44 in the front if its unlocked and you have a big 14FF locked pushing you over obstacles. I have a big block so I went to the D60.
I think that might be my sweet spot, D44/14BFF. For what I do, if I build a D44 right it’ll do everything I need it to. If I really get into wheeling I can swap to a D60 in the future…
RCV axle shafts for a Dana 44 (not 10 bolt); guaranteed up to 40" tires
Your 10b and a d44 are for the most part the same strength wise. So searching for a d44 to gain strength is a waste.
Yes, chrome-moly Shafts are available for both. Though when I was entertaining getting some for mine one thing that stuck out was the warranty went out the window if you ran tires bigger than 35’s.
Can one live with 37’s. Yes. No traction device up front would help. Chro-mo shafts too. But it will still require smart driving. Same to be said even with 35’s. I admit I’m not following my own recommendations. I’ve got a tight tru-trac helical limited slip in my D44 with stock shafts. And yes I’ve broke two shafts and a front u-joint that grenaded and wiped out both yokes and damaged the knuckle and ball joints. All three occurrences happened with a stock 5.3, 700r4, 241 and 4.10 gears with my 35’s.
I can say this all three failures occurred in similar ways. Not hammering on it. But getting stuck and going to reverse to get out of trouble. Bench racing with guys here and my wheeling buddies we came to the conclusion that the limited slip was holding torque when I was stuck and an immediate shift to reverse with no pause or delay. That lack of delay allowed the limited slip to unload and send torque down the shafts all at once in an instant. Snap! I’ve yet to break another even with the 8.1 because that also got a 5 speed swap so if I got stuck the clutch would Release any load on the drivetrain before reverse was engaged. Haven’t broke a shaft since.
Granted, had I just paused in neutral with the automatic to avoid breakage. Which i did for about a year or so before the big block went in. I still tried to drive smart. Making sure if I had to give it the beans off road, make sure the wheels were pointed straight and not push it hard if the wheels were bound up.
I’ve backed off from doing hard trails with my truck, but don’t shy away from the medium trails and lighter overlanding type stuff so the need for a d60 really isn’t a requirement. Finding a d60 at a decent price is sort of a unicorn. At least in my case most I’ve found were dually setups that require another $1500 with of parts to convert it to a single rear wheel width setup. Not to mention the need to regear to match and add in a traction device. It all adds up to more money than I want to spend.
It depends on how hard you want to push it. But mine is proof the half ton front axle can survive but you need to be smart behind the wheel. That’s also knowing my truck tips the scales right at 7400 pounds when loaded for a week long off road adventure.
If the truck is already sorted out with the 37’s and 6 “ lift and adjustments made for the driveshaft angles you are ahead of the curve. If it was mine I’d start logging some miles with it and really see how comfortable it is to drive at highway speeds, around town and on dirt. Pay attention to the steering and how it holds the road. How is it geared already with the 37’s and the automatic transmission? If you are lacking in the gear ratio dept that trans won’t be shifting into overdrive and negating the added efficiency it provides. Does it have any locker or limited slip diffs?
Since you don’t have much in off road trails nearby focus on the road manners. I’ve pushed 6hours to get to Moab and done 12-14 hours on the road to get to spots in NM, AZ and CA to explore and I never would have done it had the truck not been capable doing it first. My main point here is really getting to know the truck and develop a plan of attack from there.
You will find when you drive to far away places wheel it and drive it back there is a certain mindset that comes with it. You don’t have the luxury of a trailer to bring it home if you get stupid on the throttle. That alone will usually be a good reason to not go full hero mode off road. It’s an interesting challenge to build a truck that has both good highway manners and capable off road. Usually being better at one takes away from the other. And yes I’ve broke bad taking a trailer that was probably beyond my skill level and destroyed by 241 in the process and having to phone a friend to come rescue me and trailer my junk home to Denver from Moab. Learned my lesson and don’t want to repeat it.
Build your setup with 4.88 and don't worry about the d60 front.
With 37" tires you will be happy with the setup.
I had that setup on my k5 and it was great.
I am building a suburban now with the same setup, the only thing I am adding is RCP shafts, constant velocity shafts so I don't have to worry about broken shafts.
A rear locker will make a big difference, the front if you have the funds would help
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For overlanding light to moderate wheeling your front axle will be fine. Crossover or push pull is your choice. Push pull will bind more often in tight off camber situations, crossover is nice in the highway too. Hydro assist helps too along with mods on the steering pump to increase flow.
I have been running 14 bolt and 10 bolt with high steer, crossover and hydro assist on 37's for 20 years. Broken 2 or 3 shafts and multiple hubs, but I am welded up front, so that caused a lot of the breakage. I do a little more than overlanding. For your use that front end will hold up fine.
I have been running 14 bolt and 10 bolt with high steer, crossover and hydro assist on 37's for 20 years. Broken 2 or 3 shafts and multiple hubs, but I am welded up front, so that caused a lot of the breakage. I do a little more than overlanding. For your use that front end will hold up fine.
Run a basic hub like a Spicer or Warn, nothing extra super strong. Then the hub becomes the fuse and breaks before the axle shafts. (hopefully) Its then all right there in the hub for a trail repair without tearing down the whole knuckle.
Here are a few recipes on an actual camping trip in Utah. Remember, you're in a chevy truck so you can't go overlanding, you just go camping.
Red/grey K5:
1990 stock 350tbi/Bowtie 700R4/241 with SYE/1350 CV rear driveshaft/6 lug 14SF with ARB & 4.56/10 bolt front with Yukon shafts and ARB/35s
ORD 3" springs front and back with a variety of shock depending on what we're testing. Crossover steering with Borgeson box.
This is a really solid combo. It needs at least 50% more power to be really good to drive long distance on the highway though. I'm not worried about drivetrain strength at all and it's pretty comfortable on any sort of offroad terrain.
White K5 at that point was on some 5" ORD springs, 1 tons and 37s. It was a 305/465 and 208. I say was because it got a makeover recently and is on coilovers up front and has a Magnum and 40s now:
Given where you are now:
EFI
Rear locker
crossover
start driving it. I'd focus on making it comfortable enough to drive to Colorado, new mexico, etc which are decent road trips. General reliability, good power, thoughtless cooling systems, comfortable enough interior and probably a few more for priorities.
Then I'd look at ride quality. Days on the dirt in a rough riding truck will suck. We're big on ride quality here since our roots (the very beginning of the company actually) are in long camping trips in the mountains and desert around here.
Stick around CK5, as you can tell there are quite a few guys that know what they're doing here (we all seem to be giving about the same advice) and that's hard to find anywhere else without sorting through metric tons of BS (facebook groups...)
EFI
Rear locker
crossover
start driving it. I'd focus on making it comfortable enough to drive to Colorado, new mexico, etc which are decent road trips. General reliability, good power, thoughtless cooling systems, comfortable enough interior and probably a few more for priorities.
Then I'd look at ride quality. Days on the dirt in a rough riding truck will suck. We're big on ride quality here since our roots (the very beginning of the company actually) are in long camping trips in the mountains and desert around here.
Stick around CK5, as you can tell there are quite a few guys that know what they're doing here (we all seem to be giving about the same advice) and that's hard to find anywhere else without sorting through metric tons of BS (facebook groups...)
Actually, even basic Warn hubs (which are the same torque transfer parts as the premiums) will break stock axle shafts and most 4340 stuff. Back in the way back, Warn had the idea that the hub should be a fuse and actually had to machine special clutch rings with teeth that would break without damaging the axle and they cut about half the tooth from the ring. Turns out it wasn't a good idea because there's such a split in axle strength between full turn and straight ahead. The hub fuse idea never took off. I personally tried it and went through a handful of them and finally just put regular rings in my hubs and was mostly fine with it.
In the OPs case, a set of spare axles and tools to change them would be good to carry on a long trip and some 4340 shafts are a worthwhile upgrade. I usually carry a full time drive gear or hub assembly but most hub failures are as collateral damage when something else goes sideways.
Just to add to your confidence in what all these fine folks have replied to ya’ - not only is their advice good, accurate and effective but is thoroughly tested in real world applications and not just from some keyboard jockey wannabes.
Take some time to read through the build sections of some of these guys rigs - it’s a lifetime of learning curve acquired just by the benefit of simply reading and understanding.
Also, the last guy to post up “Stephen” is not only absolutely ate up with the sport of wheel’n and owner/operator of ORD ( Off-road Design ) but is an actual mechanical engineer that has more than just a degree - he understands the whys and why nots of what needs to be done on every level of the build.
This site is an absolute treasure trove of square body knowledge that has been tested and proven by its supporters.
Welcome to CK5 - you’ll never stop learning around here so keep on reading and asking because there’s more to it the deeper ya’ go.
