Thinking Outloud, 1991 6.2l Suburban

[mr_blasto]

I haven't been very active since I sold my '72 k5, which I bought when I was single. I now am married with 3 sons (ages 6 and under) and will likely have another child in the next 24 months. The K5 just wasn't going to work for family fun.

Fast forward to today, I've got a line on a 3/4 ton Suburban with an NA 6.2l and 4l80e running fine for about $2,000-2,500. The roof has some surface rust, and the fenders have a little. My short-term plan would be to hack the fenders, put 35" tires, stock ride height.

Short term it'd be great to keep it cheap, be able to do a little wheeling, camping, hunting with the fam as well as occasionally towing a 20ft ski boat. It'd see less than 5,000 miles a year, but must be easy to drive on the road for people who aren't used to driving a lifted truck (hence the desire to keep it low). I love the economy of the diesel and don't care at all that it's slow. In fact, I like that it is under powered because it seems less likely to break stuff.

Long-term, I'd love to go with 37-39" tires, a 14bff and D60 swap with proper gearing and lockers, crossover/hi steer, 52's in the front and 56's with a shackle flip in the rear, maybe a doubler as well. This would be pretty similar to how my k5 ended up.

Long-term it'd be more of a dedicated wheeler. Unfortunately it seems like it would also lose a great deal of towing ability with the proposed long-term suspension. I think that's a trade-off I could deal with because my wife's DD is a 1/2 ton Yukon XL, and it should handle the boat fine.

It seems like the price of this burb is pretty good, but I haven't been looking so I don't really know. Is there a better setup for a family of (soon to be) 6? I like the idea of a crew cab k30, but I'd look to shorten the bed/frame and the seating limits me more than a burb would. What would you do if you were in my shoes regarding vehicle/short-term setup/long-term setup. It'd be great to get it and get some tires on it in time for Blazer Bash this year.

 

[rebelgregory]

Sounds like a decent plan to me. Long-term it can be whatever you make it. Short term is probably what's more important. Space for the fam - check; reliable/repairable drivetrain - check. The only part that I would be concerned about is the actual performance of a NA 6.2 suburban loaded with people/equipment for the lake and towing a boat. 35" tires on stock gears only hurts towing capability, so might want to keep that in mind also.

 

[mr_blasto]

Bodies of water are within 10 miles of the boat with top speeds of 55 as I recall. I'd be towing the boat for a max distance of 40 miles (top speeds of 65) on occasions when I would need to have it serviced. If towing is miserable, I can always use my 1/2 ton yukon xl, or try to persuade my wife that the time for 1-tons and proper gearing and lockers is now The main point of the vehicle is to play, towing is a bonus, but I can work around it if needed.

 

[mr_blasto]

I guess I'm looking for feedback from anyone who has wheeled a burb and/or had a 6.2. Would you do it again or recommend either. I keep trying to think if there is a better solution, like sticking with a 350, or if a crew cab would be immensely better for some reason. I know I'm on a biased forum, but I'm just trying to get a little more comfortable with this before I pull the trigger.

 

[375 H&H]

i have the same rig, 1991 3/4 ton suburban with 6.2. i have already done the D60/14FF swap. i love it and would do it again. it is not a powerhouse, but it is not my tow rig either, and it does just fine off road. the mileage is pretty good, ~18 on the road and last weekend i drove it eight hours on everything from interstate to jeep trails and used less than 16 gallons of fuel. one day i'll do a Cummins swap, but I'm in no hurry to dump the 6.2 just yet. i do not plan on going over 33 for tires and do not want to lift, so i may have to cut fenders.

downside is the gearing kind of sucks for off road, the 4L80e has a pretty high low gear. i put 4:10s in it when i installed the 1 ton axles, but the 33" tires will pretty much put me back to stock-ish final ratio, so i am gathering parts for a doubler right now.

 

[mr_blasto]

That '72 under construction in your signature sounds awesome, but back to the matter at hand... I think I could be content with 35's for a long time, but that's what I thought last go around and I ended up replacing them with 39's when I went to 1 tons. It seems like the backside of the suburban would be hitting on everything, but apparently you're able to have plenty of fun with 33's.

Glad to hear you would do it again. It seems hard to go wrong because my specific needs to haul passengers and gear without shelling out too much $$ (which rules out a defender 110), seems to lead me straight to one vehicle. I'm a bit scared of problems with the diesel motor because I've never worked on one, but I'm drawn to the economy.

 

[rebelgregory]

One plus about learning the diesel side is you can pick up the military maintenance manuals for the CUCV free on the web. They can be a pretty good learning tool. Somewhere between a Haynes manual and a Factory Service Manual.

 

[375 H&H]

places like CK5 and the Diesel Place board are great places for help with problems/upgrades on the 6.2. make sure the harmonic balancer is not toast. supposedly they will break a crankshaft within a few miles when the balancer goes out.

I need to get back to work on the '72. it started life as a 2wd with an auto with the coil spring suspension. I did 64" rear springs with shackle flip and a b52 front kit and stuffed the motor in when I decided I should work on the '91 for a while.

 

[6.2Blazer]

Not a Sub, but I've owned a '90 K5 6.2L rig since 1994. It was my only vehicle for years and has progressed to a weekend toy to a towed off-road rig (still licensed though). I still drive it around town a little but the unbalanced 39.5's and welded rear diff don't make a great interstate cruiser. If I had the time and money I would love to have another one that was fairly stock except for a small lift and some 33-35's that could driven regularly.

With 32" mud tires on stock suspension it would get around 18 MPG and that was always running it wide open and mostly around town and backcountry roads. Never really checked freeway only mileage on the couple trips I took because it did good and back then diesel was always cheaper than gas. I also got a couple speeding tickets with it including on a 65 mph freeway...so it's not that slow. Power wise it ran okay, and it was always geared properly with 3.73 and 32's or 4.10's with 33's. I would like to see how it would do with the current minor engine tweaks of a ported J-code intake, turned up pump, and better exhaust with smaller tires.

Off-road I really like it 95% of the time. We do deal with mud and some slick hill climbs at times where it would be nice to be able to achieve more wheelspeed (like my buddy's built 460) but I have no great desire to swap out engines. The low end torque is great, basically equivalent to a fuel injected gas engine on hills, easy on fuel, and usually have enough power.

 

[mr_blasto]

I just got a few pics:
Interior looks decent

More interior, again, fine

Looks like the rear portion of the front driver's side wheel well. This shouldn't be much of a problem, right?

Fender, but I'm planning on trimming

Looks solid here

Also looks trouble free here.

They are some random shots he took for me. Would I be over-paying at $2,000 given rot, rough paint etc.? He's put about 20k miles on it over the last 2-3 years, so it surely isn't a basket case or anything. about 150,000 total miles right now. Engine hasn't ever been rebuilt. Thoughts?

 

[kennyw]

Being that you are in ca, the rust is a big issue that helps bring the price down. But, being a diesel brings the price up for lack of smog. $2000 sounds like a good price for the area and a good deal for you since you were going to cut it up anyway.

 

[muddysub]

thats some pretty minor rust, i'd buy it. i love that the 6.2L gets such awesome mileage, even if it isn't a powerhouse. the 4L80E is a solid trans too. like i said, i'd buy it. keep it low, stuff some tire in there and have fun! the longer wheelbase is more capable that you'd expect.

 

[diesel4me]

Actually a Suburban (square body ones at least) had a slightly shorter wheel base than a long bed pickup (Suburban 127.5" vs 131.5" for an 8 foot pickup)--so the Suburban will have a slightly tighter turning radius...I can "feel" the difference driving my '85 Burb vs the '82 K2000 pickup in the turning radius and handling...

What "kills" the Burb off road ability more than anything is the longer overhang behind the rear wheels,the back bumper and gas tank are likely to hit bottom when you decend a steep banking--thats why most of them had factory skid plates..

 

[muddysub]

Actually a Suburban (square body ones at least) had a slightly shorter wheel base than a long bed pickup (Suburban 127.5" vs 131.5" for an 8 foot pickup)--so the Suburban will have a slightly tighter turning radius...I can "feel" the difference driving my '85 Burb vs the '82 K2000 pickup in the turning radius and handling...

What "kills" the Burb off road ability more than anything is the longer overhang behind the rear wheels,the back bumper and gas tank are likely to hit bottom when you decend a steep banking--thats why most of them had factory skid plates..

hmm, i thought suburbans were 131" as well. i'll have to check mine. and yeah the rear overhang is the downside.

 

[mr_blasto]

Yeah, I'd love to do a crew cab on a suburban frame, and chop the frame as short as possible, but I'd lose a lot of seating. Maybe I can look at that when my oldest is ready to drive, and at that point we could wheel with two rigs. For the next 10 years or so, it seems like we'll be enjoying a suburban. The nice part is the boys will be stoked just to do any off-roading, so it's not like I have to do an extreme build right off the bat. We can ease into it as needed.

I'm hoping to work this out so we can take it to blazer bash this year, but we'll see if I can make it happen or not. It doesn't hurt to dream, right?

 

[campfire]

I would buy it. 6 months ago I wanted nearly exactly that combination for a very similar purpose. People hauling and road trips with light offroading & trailering on the side. I thought that a burb would fit the nitche better than a cclb would have, as the rear section can be cargo space or passenger seating (better flexibility). And I wanted something that was also cheap to drive. I ended up buying an '84 suburban that is similar to this one (see link in sig line). On the road, I wouldn't swap my 6.2 for a small block. Even if the fuel mileage was comparable. I find the flatter torque curve makes driving more fun (less downshifting). My '83 K10 is geared for cruising, the burb is geared for towing. I don't think either of them holds up traffic, although the power difference is noticeable.

There are a few advantageous features to having a '91 vs. the older models (4L80 and surpentine belt setup, among others). There are a few diesel-specific quirks that you will end up learning (mostly related to fuel system priming), but nothing particularly difficult. And several simple modifications that can be performed if you do end up wanting more power at a later point in time. I think your idea sounds great. And I'd jump at it, seeing it's a late-model 6.2.

 

[mr_blasto]

It's official. I bought it, but I'm not in the same state as the vehicle, so pics will have to wait. I'd love a "CK5 Sub Culture" sticker, but it looks like the sticker I'm looking for isn't available. Maybe that will have to be the first project, ha