1992 Blazer questions

[pevrs114]

Gents,

First off I wanted to say hi. I've been a lurking member here for years, but finally paid up and can post. Some of you may recognize me from AR15.com or SteelSoldiers. I have a few quick questions regarding a truck I'll be getting next week, hopefully you guys can give me a hand.

I'm going to pick up a 1992 full size Blazer. It's extremely clean, no rust, and well maintained. It has 88k miles on it, with a stock drivetrain (350tbi, 4L60(not e), NP241, 10 bolt, and IFS front. I'm assuming it's 3.73 geared, but I haven't confirmed it. It's a Silverado edition, with plenty of power options. It's bone stock, other than twin tail pipes and a bit of chrome flashing (yuck).

I'm already looking at upgrading it (hey, who isn't?). The primary use for this truck will be a capable daily driver, which can tow, do light off-roading, camping, and general reliability. I'm not looking for anything extreme, but I'm planning my mods now to be overstrength and overthought for what I'm looking to do.

I already have a Warn Classic bumper and a Warn M12000 for the front. Plenty of comm gear and standard compliment of recovery, camping, and bail-out equipment to keep inside.

First issue is springs/lift/tires. I'm considering running a BFG AT in 33x10.50, which is a narrow tire. I'd prefer not to incur the costs of regearing, hopefully the truck will be able to run these without significant loss of power or strain on the front end. Will a standard 15" steel wheel from the square body style fit over the brakes on this truck without any problem? Would I run into any backspacing issues?

I'm considering upgrading to K3500 torsion bars for the improved GVWR, especially with the heavy winch on the front. Will they drop right in with minimal fuss? Will I need to adjust them to clear the tires, and if so, what would be a good set of keys to do it with? I have a PN for Ford expedition keys, but I've gathered they just fit the half ton torsion bars. I'd really like the increased weight rating of the one ton bars. Anybody have a PN for keys and torsion bars that will help out?

Down the road, I'm considering a 6 lug 14SF and 4L80E. I don't really plan to wheel this truck hard (I have other vehicles for nasty trail riding) so I don't see the advantage of a SAS. Thus, I want to keep 6 lug in the rear. I figure the heavy half rear would provide an upgraded towing, braking, and strength capacity while minimizing the snowball costs of 8 lug projects. What years and models does this axle come in? Any gremlins to look out for?

I'm also considering a 4L80E for the same reasons. I'd like to keep an OD transmission, otherwise the TH400 I've already got would work just fine. What is a good expected range for a well-maintained used heavy duty trans? Any problems bolting it in place? I've got the TH400/208 combo already so the adapter should work to connect the 4L80E/241, correct? Any changes in driveline length? What will I need to do to run the electronic part of the trans, as the current trans is not an -E model?

Sorry for the barage of questions, I'm new to the IFS series of trucks. I am not looking to make this thing hog-wild, it will probably end up looking mostly stock on the outside, but I'd like to strengthen it up for durability and reliability purposes.

Just so no one worries, I've also got an 80 CJ7 and an 86 K30 CUCV to play with. The K30 currently has an oak tree sitting on the cab DOH! So it's drivetrain will get scavaged and combined with other stuff, hopefully into a square body crew cab!

Thanks in advance...

 

[AJMBLAZER]

If you want 33x10.5's just get some 255/85R16's on the stock wheels. If a bit wider go for 285/75R16's. They'll fit just fine on a stock height truck if you use wheels with similar dimensions to stock.

Decent enough truck. I had a '92 for a while that my parents had since new. Was in the family for 10 years and I did a lot with it including some stupid stuff. Definitely don't lift it.

Higher rate bars will just bolt in. Don't get the keys.

Check the front steering parts, especially the idler arm. That year has the craptastic 2 bolt setup that is known to fail. I do believe there's an upgrade now though.

A well built 700R4 will handle anything a 350 TBI equipped Blazer K1500 can tow. Dad killed the stock 700R4 in mine/ours and paid a bunch to have it built well back in '97 or so. Worked great for teh rest of the time I owned it ('98-2002).

Good shocks, narrow 33's, beefed trans, quality steering parts, good hitch setup, and don't expect it to be a 3/4 ton Burb and it'll do what you want. I wheeled mine pretty hard and it did well until I got into the "you should have a SAS" places...then I had troubles. It towed my folks' 26' travel trailer decent but did get pushed around some. DON'T LIFT IT obviously.

14SF swap would be cool but I'd not worry about that until you need to. It's got the 30 spline 10 bolt right now so you're better than some.

Random, check the windshield wipers function. That was the era of the cracked solder on the circuit boards in the motors. Mine developed that problem.

 

[noJeepshere]

What he said ^^^ Plus:

265/75-16's are the "larger" factory option size tire that these rigs came with. I have 265/70-17's on my 99 Yukon right now, and the larger wheel size helps a bit on the road, and doesn't have any drawbacks off road either.

Did the pre-vortec motors have the loose bolt/ gasket failure problem, or is that just a vortec thing? Either way, it's annoying.

Check the idler arm for sure, mine is wearing out and needs to be replaced soon. Against AJM's judgement, I'm going to say that it's ok to crank the torsion bars enough to make it sit level unloaded, but DON'T LIFT IT. GM ifs is marginal at best and gets even worse with lift.

Axle swap or no, I'd recommend upgrading the brakes at both ends, as the factory stuff is ok by itself and can really be overwhelmed with a trailer. And for the rear semi-float, get disc brakes for two reasons, better brakes and axle retention. If the axleshaft or c-clip fails, the rotor/caliper setup can hold the axle in and let you get home safely. It's a nasty mess when the wheel walks sideways out of the axle when that fails.

 

[AJMBLAZER]

Cranking to maintain ride height or a bit more is generally okay. You can align them successfully with about that much...but you are loosing down travel.

That age should have had the 265/75R16's stock. Only the super el cheapo stripper package Blazers got the 245's. GM started cheaping around the mid 90's and went to 245's as most.

Nope, no bolt/gasket issues with these. Standard GM TBI 350. Not exactly a powerhouse but stupid reliable and simple.

 

[noJeepshere]

I'm just giving you a hard time because I remember how much grief you gave me about it

 

[AJMBLAZER]

Cranking the **** out of them like most folks do?

Bad idea.

Leveling the truck?

Probably not provided the suspension isn't already sagged.

Leaving it stock?

Probably the best option since we are dealing with Inferior Front Suspension here.

 

[Doc Feel Good]

I have a 92 K1500 Blazer (Silverado Package) and its my daily driver.

I am running the stock 265/75R16. It does ok for the snow trips and simple hauling duties.

The only thing I dont like about my rig is the brakes. It just doesnt feel right to me. But I am very picky.


Upgrades I have made:

intake Performer RPM TBI
Hypertech Chip (second stage, the more aggressive one, but still passes smog)
Double Roller Timming Chain
GM cam upgrade (not sure of the specs, but Crown Chevy parts dept called it the 290hp upgrade for the TBI)
High flow RV cat
Magnaflow single high flow exhaust

My rig is not a wheel spinner, but not the dog it was stock.

-Doc

 

[AJMBLAZER]

A bit of TBI mods and that sounds like what I was planning for mine.

Yeah, if lots of towing or hard use was involved I would say researching disc brakes would be a good idea.

 

[pevrs114]

Excellent info guys. As soon as the snow clears out, I'll try and get some pics.

Vehicle is a 1992 Blazer (Silverado Edition), and it's pristine. 88k miles, was kept garaged its entire life. My dad knows the guy who traded it into the dealership, he's an over-the-road trucker.

Only problems I've found so far is that it's running a bit rich, I can smell the unburnt fuel in the exhaust and getting about 10mpg around town. Also, how do you turn off or reset the 'Service Engine Soon' light? I changed the oil, but I haven't changed the air or fuel filters yet.

Other than that, gonna change fluids in the trans, xfer, and diffs, and start upgrading it. Got a Warn X12 12k lb winch and Warn Classic bumper sitting nearby to go on it, and a bank of radios and other electronics to go inside as well.

Thanks again!

 

[AJMBLAZER]

Do you have a Chilton's for it? That has the code reading and resetting procedure. The quick and dirty way to do it is to just unhook the battery for about 10 minutes. However if the code is an actual problem it will just reappear as soon as the computer recognizes it.

 

[noJeepshere]

If the local stations have ethanol, the light may never go off. Technically there is nothing wrong with my Yukon, but the light stays on because the ethanol burns hotter and triggers a code.

 

[Doc Feel Good]

Unburnt fuel... sounds like an EGR valve issue.

You might want to check it out.

My rig is also in very good condition, I paid 4k for it a few years ago, it came with 108k miles on it.

Now I am up to 129k. You may want to check the actuator on the front differential. Mine was bad, according to the dealer its a common issue with that year.

-Doc

 

[AJMBLAZER]

Common with all of them of the era. The best replacement is the 4x4 Posi-Lock. Loved mine, only time I was ever sure the front was engaged and staying that way.

 

[noJeepshere]

The later ones that were mechanically actuated (like mine) were much more reliable. 10 years and 150,000 miles and it has never once failed.

 

[pevrs114]

Well the scan tool said it was running lean, and so the FI computer was throwing too much fuel to attempt to match the extra air. I'll be changing the fuel filter and O2 sensor just for good measure, the parts guy also suggested checking the Idle Air Control Valve. I pulled it out and it was sticking, I hosed it out with some carb cleaner and the truck seems to be idling much lower now (700 rpm instead of 1500). I haven't been through a full tank of fuel yet, but it seems to be running much better. Hopefully that fixed it!

I'll definitely check on the Posi-Loc

 

[AJMBLAZER]

The later ones that were mechanically actuated (like mine) were much more reliable. 10 years and 150,000 miles and it has never once failed.

They're okay but for the cost (last I knew) you could get a Posi-Lock for not a heck of a lot more and that's mechanical and won't disengage when you turn the truck off.

 

[dhcomp]

I have a 92 K1500 Blazer (Silverado Package) and its my daily driver.

I am running the stock 265/75R16. It does ok for the snow trips and simple hauling duties.

The only thing I dont like about my rig is the brakes. It just doesnt feel right to me. But I am very picky.


Upgrades I have made:

intake Performer RPM TBI
Hypertech Chip (second stage, the more aggressive one, but still passes smog)
Double Roller Timming Chain
GM cam upgrade (not sure of the specs, but Crown Chevy parts dept called it the 290hp upgrade for the TBI)
High flow RV cat
Magnaflow single high flow exhaust

My rig is not a wheel spinner, but not the dog it was stock.

-Doc

To properly bleed those brakes, you need a real scan tool. There is a mode to get ABS control box to open all passages or something so you an get the air out properly. Never figured this out in the 100k i had the truck, but talked to someone afterwards that finally got a firm pedal.

So w/o "talking" to the abs box with a scan tool, you will always end up with a squishy pedal when you bleed traditionally.

 

[noJeepshere]

They're okay but for the cost (last I knew) you could get a Posi-Lock for not a heck of a lot more and that's mechanical and won't disengage when you turn the truck off.

Yes and when my mechanical actuator craps out I'm replacing it with a posi-lock.

 

[AJMBLAZER]

Funnily enough today I found a bunch of shots of mine I had long since lost.




I still miss it, big POS that it was to me.