91 Suburban 2500 restoration

[91 Suburban 2500]

Hi All,

Had a family member gift a '91 Suburban 2500 to me today. The overall shape great but it sat for the past 15 years in So Cal heat. Paint is gone, some engine harness wires chewed through, and could use some love.

Fully loaded with a 454 on a factory new 80e Trans.

Some other issues are that it wanders down the road a bit like its toe is out. Before it got parked, it went to alignment shops, tire shops, and no one could figure it out.

VIN is 1GNGR26N2MF113784

It will be used in towing an classic car on a trailer. What upgrades should i look into? Brakes? Cooling? Radiator?

Best

 

[SUBURBAN5]

That would of been a square body burb right? Didnt know they Came with the 4l80trans lol. What I recommend is a brake upgrade maybe performance type, upgraded cooling and trans cooling system. Make sure all your steering components are good. If no rust undercoat the bottom. See if the r12 works otherwise consider r125 conversion. Maybe new lights, send pics btw lol

 

[HotWheelsBurban]

Yes 91 is the last year for square body Burbs. 92 was the first 400 one. I used to have a 90 R2500 Burb, and it had steering issues like yours. What dad and I ended up doing was replacing the tie rods and lower ball joints, idler and pitman arms, and complete upper control arms to get new bushings, shafts and upper ball joints. This was done by us over the course of a couple years.
Being a 3/4 ton 8600gvw rated truck, ours had tall skinny 16" tires on factory steel wheels. I called them " pizza cutters ". Big old brick truck was really hard to keep on the road straight in much of a wind before the repairs. Square trucks are hard on idler arms and ball joints. If you're having tire wear on the inside edge, that's a sign of bad ball joints. Also, good alignment shops are hard to find. Just because they have the equipment does not mean that everyone can use it and know what they are doing.
I would also recommend looking at the wheel bearings. If they are bad or not set up properly, it can result in poor steering too.
As far as the cooling system, be sure you have a good water pump and hoses, and that the radiator is sound. That truck should a severe duty fan clutch, with lots of fins. If you're towing, you need this item. The brakes should be the 11 5/32" drums on the back. Those should be adequate if in good condition. If you go into them, look closely at the condition of the shoes,wheel cylinders and hardware parts. The drum brake hardware is often overlooked, and kits for Chevy trucks are reasonably priced. Well worth starting fresh with new stuff if any doubt about condition, and lubricate the wear points with appropriate brake grease.
454 Burb should have a big radiator in it,probably 4" thick core and tanks. Should be the old style brass instead of the plastic tanks/ aluminum core that the 400s use. Much better, don't leak as much.
Sounds like it will be a good truck for you with a little bit of sorting out.....please post updates.
Hope this helps!
And yes pictures of it will be appreciated!
Our truck had been converted to R134a before we got it. Worked great in front and rear air as long as the system was full of freon.

 

[91 Suburban 2500]

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Pics as requested. Dumpster got away from a family member and found the driver door. Interior is flawless.

 

[91 Suburban 2500]

That would of been a square body burb right? Didnt know they Came with the 4l80trans lol. What I recommend is a brake upgrade maybe performance type, upgraded cooling and trans cooling system. Make sure all your steering components are good. If no rust undercoat the bottom. See if the r12 works otherwise consider r125 conversion. Maybe new lights, send pics btw lol

4l80e trans is the 2nd trans to go into this Suburban. The trans is factory new but i don't think it was the original. I'm looking around for a upgraded Radiators/trans coolers and i must admit, not having much luck, have any product numbers or manufacturers to go towards?

Best,

 

[stutaeng]

Upgrades? Probably nothing. It should have the big radiator and I think you have hydroboost brakes, so that is good for towing. So you don't have factory transmission cooler? That should be an easy mod to add cooler. Do you have engine oil cooler? Power steering oil cooler?

Being an square body, look at the trucks from that generation for mods. Specifically, the BBC models.

I think the very early 4L80e had some issues with the oil not cooling and some parts burning up:

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Replace the tires for sure and probably most all rubber hoses under the hood are dried out from sitting for so long. Change all oil/fluids/coolant also.

 

[SUBURBAN5]

Well suburbans are badass vehicles lol. I'm not much of an aftermarket brand wizard. My suburban set up is pretty much stock with ac delco parts. Different gen different set up 5.7, 4l60e,342, hardly ever tow lol. But my set up has worked pretty good. The one thing I added was a steering cooler. The truck already equipt with transcooler, trans aux cooler, oil cooler, and I plan on adding a aux condenser fan for the ac whenever I'm stuck in traffic lol. I would copy that if your is missing some coolers. HotWheelsBurban actually owned a few squarebody so I would follow her advice. If you tow a lot I could see getting thicker cores/coolers. As far as brake rotors and brakes I'm planning on gmt800 master cylinder, stainless brake lines and maybe performance rotors. Also the bigger rear wheel cylinders. Again different set up then yours but I'm sure you can do something for that model. Yours being hydroboost is better set up then me, but I dont want to convert to that lol. New/rebuilding the front end goes a long way like mentioned already above. Wish I could help more but I've only owned the gmt400 platform. So I'm limited for the squares. Goodluck ask questions and I'm sure plenty of guys here have there own advice/experience. Also what you plan on doing with it has different results Racing/stock/towing/lowering/ect...

 

[HotWheelsBurban]

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Pics as requested. Dumpster got away from a family member and found the driver door. Interior is flawless.

Looks like a good old truck that just needs some love and attention. Mine was a GMC and had barn doors instead of the tailgate and electric window like our other square Burbs had.( My family's had lots of Suburbans; 75,77,79, and 84 in addition to the 90 I mentioned before. )
I second what Suburban5 said about the hoses and rubber bits. I also had a Dodge Intrepid for a number of years, and in the middle of this time it sat for several years because of fuel and timing problems. When dad and I got it running again, we replaced every hose under the hood. It had several molded bypass hoses that had to come from the dealer. But after replacing them( and the clamps with stainless steel worm drive ones) it never leaked.
If you have any more questions about this truck, ask away! I don't know everything about square body Burbs, but I will help you with what I can.