LT1 T56 swap possible? Opinions please

[K10Dream69]

Starting with the bad news first, my buddy wrecked his 96 Formula. The LT1 has had a lot of money put into it. The car was pulling high 11's in the 1/4 mile.
Now because I'm a gear head I'd like to get ahold of this motor and tranny for the old girl.
Right now I have a 454BB with the granny 4 spd, sits on 35's with 410's.

I'd really like to do a swap and utilize his setup. Now I know people use the LT1's in these trucks with a 4L60E, is there any possible way to make a T56 work with 4wd?

I understand with unlimited $ anything is possible. But trying to weigh my options.

Thanks for any input

[Fitz]

Originally Posted by K10Dream69

Starting with the bad news first, my buddy wrecked his 96 Formula. The LT1 has had a lot of money put into it. The car was pulling high 11's in the 1/4 mile.
Now because I'm a gear head I'd like to get ahold of this motor and tranny for the old girl.
Right now I have a 454BB with the granny 4 spd, sits on 35's with 410's.

I'd really like to do a swap and utilize his setup. Now I know people use the LT1's in these trucks with a 4L60E, is there any possible way to make a T56 work with 4wd?

I understand with unlimited $ anything is possible. But trying to weigh my options.

Thanks for any input

Any swap is possible. It's just a matter of the amount of work involved. The tough part will be getting that trans to match up with the transfer case. Rockland Standard Gear is making an adapter for mating a Tremec T56 6 speed transmission for 4 wheel drive pickup trucks.

[Mike C]

Anything can be done, but honestly, the T56 gear ratios bring the suck for a 4x4. The 2.97 first gear of the widest ratio T56 is the same as the 1st gear in the 3 speed in my '79 jeep. I have a built 360 in my jeep with 3.54 gears and even in low range I have to work the clutch to get my bassboat up the ramp. (and it's only a 16 footer!)

4.56 gears and a different trans and maybe even t-case are in the jeeps future.

The SM465 is a MUCH better transmission for a 4x4 and will be no issue bolting up to the LT1. It just won't be a racer as you know how slow it shifts!

[cooperhw]

The LT1 is a great motor and would make a good one in your truck. I had one in my last 70 Chevelle and it ran like stink.
The T56 is a great transmission but don't think it would be good in your truck. Even high first gear in my 67 Chevelle street car right now. I would never put it in a 4X4.
Good news is the T56 is a very sought after transmission that you could sell and buy a great trans for your truck.
Right price and I would pick it up for sure.
J.M.O.

[K10Dream69]

Originally Posted by Mike C

Anything can be done, but honestly, the T56 gear ratios bring the suck for a 4x4. The 2.97 first gear of the widest ratio T56 is the same as the 1st gear in the 3 speed in my '79 jeep. I have a built 360 in my jeep with 3.54 gears and even in low range I have to work the clutch to get my bassboat up the ramp. (and it's only a 16 footer!)

4.56 gears and a different trans and maybe even t-case are in the jeeps future.

The SM465 is a MUCH better transmission for a 4x4 and will be no issue bolting up to the LT1. It just won't be a racer as you know how slow it shifts!

Ok, so sounds like the T56 isn't going to work for this 4x4. I REALLY wanted the extra gears to make it drive nicer. I'm in Nevada and almost every where you go is freeway at 65mph.

He's looking to get $1500 for the pair, says he'd throw in the LT's on the car for me too.

I know I can sell my BB and most likely get half of the $ then sell the T56 and come out pretty close to getting my money back.

Thanks for the input! Time to figure out where to find the $$.

[LockDoc]

-
You might consider the NV4500 5 speed overdrive. It has the low 1st gear "and" overdrive.

LockDoc

[Mike C]

What tires and gear are in your truck? I have 4.10's with 35" BFG AT's and it cruises pretty well at 65, 2500 rpm or so which is a carburetor sweet spot. 75 not so much...

[special-K]

On a 4wd I use tall tires as overdrive and gearing/tq for bottom end.

[K10Dream69]

Originally Posted by Mike C

What tires and gear are in your truck? I have 4.10's with 35" BFG AT's and it cruises pretty well at 65, 2500 rpm or so which is a carburetor sweet spot. 75 not so much...

That's the same setup I have. 35's with 410's. I agree, 65 the truck is fine. Over that not so much.

[K10Dream69]

So after doing some research last night, upon seeing the cost of the Painless wireharness, factoring in new motor mounts, and i'd have to upgrade my cooling fan, let alone all the extra misc. things that would come into play.

Reality of this is getting it painted and put back together is more important then this swap.
So I decided to steer away from this idea. I'd like to do it but throwing an extra $3-5K at this isn't possible right now.

Thanks for all of your input

[MARKDTN]

Originally Posted by K10Dream69

So after doing some research last night, upon seeing the cost of the Painless wireharness, factoring in new motor mounts, and i'd have to upgrade my cooling fan, let alone all the extra misc. things that would come into play.

Reality of this is getting it painted and put back together is more important then this swap.
So I decided to steer away from this idea. I'd like to do it but throwing an extra $3-5K at this isn't possible right now.

Thanks for all of your input

Use the harness out of the car, why do you need new mounts?, why would you upgrade cooling fans from a BB to an LT1? I don't see why you would need $3-5K for this swap.

[Mike C]

He can't run the big block mechanical fan. But there is an LT1 mechanical fan setup out there that was found on some HD cooling cars. Maybe cop cars, wagons, taxis, etc.

[K10Dream69]

Originally Posted by MARKDTN

Use the harness out of the car, why do you need new mounts?, why would you upgrade cooling fans from a BB to an LT1? I don't see why you would need $3-5K for this swap.

I wasn't sure if you could use the old harness or you had to get a new one. I always see people saying Painless Wiring Harness. Can you add the harness without upgrading our existing fuse panels in these trucks?
Big block to small block would be different motor mounts no?
The LT1 isn't setup with the mechanical fan so it would be $500+ to add electrical fans to it.

I'd like to use the LT1 instead of the BB, not only does it have more HP it would get better gas mileage which isn't a big deal but overtime it would add up.

Sorry for all the ?'s, just looking for input.
Thanks

[MARKDTN]

Originally Posted by K10Dream69

I wasn't sure if you could use the old harness or you had to get a new one. I always see people saying Painless Wiring Harness. Can you add the harness without upgrading our existing fuse panels in these trucks?
Big block to small block would be different motor mounts no?
The LT1 isn't setup with the mechanical fan so it would be $500+ to add electrical fans to it.

I'd like to use the LT1 instead of the BB, not only does it have more HP it would get better gas mileage which isn't a big deal but overtime it would add up.

Sorry for all the ?'s, just looking for input.
Thanks

I would not use a Painless harness for anything. The fit and finish is minimal. If you have the whole car, you could take the harness out and just use what you need. You will need the PCM re-flashed to remove a bunch of OBD2 stuff.

Depending on how you do or don't do A/C is if you can use existing mounts. SB mounts are cheap. the A/C compressor may be in the way of the passenger side mount. If you don't have A/C it probably isn't an issue.

Fans-look at B-Body HD fan setup for '96 Impala SS. That is a mechanical fan. You would need a junkyard to get the fan, idler, and lower pulley. Or electric fans could come off the donor car. You would have the fans and harness. The LT1 motor alternator is plenty.

[LockDoc]

Originally Posted by K10Dream69

I wasn't sure if you could use the old harness or you had to get a new one. I always see people saying Painless Wiring Harness. Can you add the harness without upgrading our existing fuse panels in these trucks?
Big block to small block would be different motor mounts no?
The LT1 isn't setup with the mechanical fan so it would be $500+ to add electrical fans to it.

I'd like to use the LT1 instead of the BB, not only does it have more HP it would get better gas mileage which isn't a big deal but overtime it would add up.

Sorry for all the ?'s, just looking for input.
Thanks

You would want to get the harness and ECM for the LT1. The engine harness is pretty much separate for the engine, although a few wires tie into the truck harness. Other than that you don't have to mess with the truck harness or fuse box at all.

I think the BB mounts will bolt right up to the LT1 block and by using them you won't have any clearance issues no matter what you want to use for exhaust manifolds/headers. I haven't checked into fans yet but i am figuring no more than $200-$250 and less if I can find some in the salvage yard.

LockDoc