'91 GMC 'burb 4x4, need help planning project

[a58chevy]

I have a '91 GMC Suburban 4x4 that I bought to haul band gear with for $1500. Body is in great shape but this weekend I think the timing chain jumped and I think I bent a valve on the freeway. The trans also was leaking pretty bad.

It currently has a tbi 5.7 with 700r4. I want to go 5.3 or 6.0 depending on cost and availability.
So I've never owned a 4x4 (don't plan on doing alot of off roading, mostly for snow driving ability) so I want to know what exactly I need transmission wise. If I buy a built 700r4 are there any specific needs for 4x4?

This will be a carbed swap. I have the carb aspect figured out but I have some more questions.
1. header suggestions?
2. what motor mount adapter do you guys prefer?
3. how do i run a belt with ac delete?
4. do you guys run the new style alt and ps pump or use vehicle stock?

any other tips you guys have will be greatly appreciated.

[okieraptor]

Few questions.

Why carb it. The fuel injection will net better fuel mileage.

why not just rebuild your tranny?

If your goin to be hauling band gear fuel mileage will be your friend and so will the ac. With the ac off you loose no mpg's but if you get hot its still there to use.

I would try to find a motor/tranny(4x4 tranny without the transfer case) out of a wrecking yard and use the whole setup. You live up north so the cold weather starting and reliability of the fuel injection will be worth it. Just use you stock transfer case so you don't have to wire up the electronic switch that ingauges the 4x4.

[a58chevy]

The main reason to go carbed for me is it's cheaper initially. Not to mention I don't have to re-do a fuel system, or program the comp to run a different cam.

The reason I was thinking of a th350 is because the truck has 32" tires and I believe the 3.42, maybe 3.73 gears.. we drove about 400 miles on the freeway and with a full load the trans up shifted into 3rd quite a bit anyways, especially any bit going uphill.. although that could be due to the fact the motor seemed pretty tired. Honestly part of it is hearing the stories of people grenading freshly built 700r4's. I can't afford to do that and I've never messed with one. TH350 just seems simple but I could be convinced otherwise.

As far as AC it's a very rarer occasion we get anything more than 80 degrees, not to mention somebody started to remove part of it and never finished the job.

As far as fuel mileage I don't care anymore.. I just lost almost $1000 on a honda just to keep it going only to have it break down again in 4 months. I'm done with technology, like the phrase K.I.S.S. I'm still on the fence about just rebuilding the 350 that's in it, but an LS swap seems easy enough. Computers and fuel injection are great until they fail, that's when you start spending on the parts to fix.... all the gas mileage in the world won't help me if the car won't stay running and I can't afford to pay someone to fix it. That's just my opinion though.

[Damien]

The Gen III engines use a separate belt for the a/c compressors. Leave the belt off. I would also look into keeping it fuel injected. The price of the intake and ignition controller is about the same as reworking the harness and getting a tune. You can also run a 4l60e in place of your 700R4. You can put a high pressure pump in your stock fuel tank.

[okieraptor]

Ok I agree with Damien. It will cost just as much for the carb setup as the fuel injection tune. Now I see you coming out ahead if there is noone down the road to tune it. Either way you will have more power than before.

On the 700r4 problems its almost always do to the tv cable not set right. I'm very hard on trucks and never had one fail without 150 or so thousand miles on it. A buddy of mine has one in his blazer with 37" tires. Its a stock tranny with 50,000 miles of burried to the doors or more mud. IMHO set up right the 700's are as stout as any out there.

Also iv seen 700 live behind 500hp big block's

[a58chevy]

I was looking at a TCI 700r4 on summit. I didn't see any options for 4x4, are they all the same?

Also I've been reading through some old car mags and researching the the two stand alone self learning TBI setups.. the powerjection III and the fast ez-efi.. I might be ahead of the game to run something like that on a built up 350 or 383 stroker rather than a 5.3 in a heavy suburban.

Not to mention I'm not really finding any good headers other than shortys for LS in my year... and I do have 3 350 blocks laying around...

I can't make up my mind............

[z3pr68138]

Headers. I would go with Doug Thorley Tri-Y headers.

[okieraptor]

A solid built 383 will cost about the same as a 5.3 or 6.0 maybe a little less. For the cost of a tune and harness or the complete carb set up you can rebuild your tranny. Plus if you use the 383 with a mild cam you can use the stock fuel injection.

[85burb]

Sorry to butt in... Do those headers actully fit a 73-91 burb?

I am doing a 6.0 Carb swap on my 85 burb. It is about same EFI or carb. But with carb you can tune your self if you put upgrades on.

[z3pr68138]

Doug Thorley Tri-Y headers are made to fit many vehicles. The set I had on a 89 K5 Blazer fit very well. No clearance issues at all. I ordered mine through Summit. They cost alittle more then most headers, but well worth it in my honest opinion.