Best manual transmission for 350 small block

[DaddYankMe]

So i have a 1991 gmc sierra 1500 with a stock small block 350 and it has the hm290 manual transmission i rebuilt 2 weeks ago

So im plannin on putting a little more hp on the engine about 300 to 400 hp but i wanted to keep it manual but I heard these transmissions are wimpy

My question is it possible to upgrade this transmission? Or should i swap it out for another stronger manual transmission? If so what are some good manual transmissions out there that would directly fit ?

 

[someotherguy]

It'll last as long as you don't beat on it. They are indeed wimpy. I was surprised when my buddy's held up behind a 502 big block until he clutch dumped it a few too many times and broke the case.

Richard

 

[0xDEADBEEF]

I would say a T56 is the most common upgrade path.

 

[DaddYankMe]

It'll last as long as you don't beat on it. They are indeed wimpy. I was surprised when my buddy's held up behind a 502 big block until he clutch dumped it a few too many times and broke the case.

Richard

It'll last as long as you don't beat on it. They are indeed wimpy. I was surprised when my buddy's held up behind a 502 big block until he clutch dumped it a few too many times and broke the case.

Richard

Dam thats surprising tbh i didnt think it would be able to handle that much power
But incase if i do wanan swap what do u recommend

 

[someotherguy]

Dam thats surprising tbh i didnt think it would be able to handle that much power
But incase if i do wanan swap what do u recommend

The T56 mentioned comes from someone with a whole lot more experience than me! New, they're a small fortune. If you do some research you can find them used in a variety of applications, some may be more suited than others for a swap into your truck.

I was really surprised with my friend's truck, too. I kept warning him how weak those transmissions are, and I think he just didn't care, as he was planning to swap it to something else once it grenaded. So he grenaded it. It took a while, though! Lack of traction may have helped it live.

Richard

 

[DaddYankMe]

I would say a T56 is the most common upgrade path

Does that come off a covette ?? And is it a direct fit or do i need to do some adjustments for it to fit ?? Plz tell me more i just saw one for 500 bucks on facebook

 

[DaddYankMe]

The T56 mentioned comes from someone with a whole lot more experience than me! New, they're a small fortune. If you do some research you can find them used in a variety of applications, some may be more suited than others for a swap into your truck.

I was really surprised with my friend's truck, too. I kept warning him how weak those transmissions are, and I think he just didn't care, as he was planning to swap it to something else once it grenaded. So he grenaded it. It took a while, though! Lack of traction may have helped it live.

Richard

Does the t56 come out off a corvete ??? And is it a direct fit or do i need to do sum adjustments for it to fit ? And does it need to be tuned ? And Im new to all this so i dont knke much and man i just wish i could of know before rebuilding the hm290

 

[0xDEADBEEF]

I believe all Corvette T56s are only found in the C5 and up, are rear mounted (transaxle).

I think your best option is a 1993-1997 Camaro/Firebird

 

[someotherguy]

Does the t56 come out off a corvete ??? And is it a direct fit or do i need to do sum adjustments for it to fit ? And does it need to be tuned ? And Im new to all this so i dont knke much and man i just wish i could of know before rebuilding the hm290

I found this just by searching "t56 transmission" - it might be helpful: https://www.motortrend.com/how-to/e...ow-about-selecting-a-t56-for-your-gm-project/

I say you already invested the time, effort, and money to rebuild your existing transmission. Treat it with care and it should last. Just save your money and develop your plan ahead of time for the upgrade for when it does blow up.

Richard

 

[Erik the Awful]

Does that come off a covette ?? And is it a direct fit or do i need to do some adjustments for it to fit ?? Plz tell me more i just saw one for 500 bucks on facebook

If you legitimately found a T56 for $500 and it's not a shell filled with crunchy gears, you better jump on it.

Manual transmission lifespan is very much dependent on driving style and torque. Smooth drivers can get away with a weaker transmission, but the higher the torque input, the smaller the margin of error becomes.

One side of my brain is saying that an engine that makes 500 horsepower at 4000 rpm will be harder on a transmission than an engine that has to rev to 6500 rpm to make 500 hp, but that would be horsepower. Torque is torque. Replace "horsepower" in that sentence with "torque" and both transmission are equally in danger. Anybody able to speak more knowledgeably on this?