c3sleeper

I've got an 81 and am putting a 460 horsepower crate motor in it. Will the Super T-10 be able to handle it? It has a 2.72 rear and the rear tires are 275-60-15 Goodyear Eagle GT-II.

tyancey00

did you swap the rear? the 4 speed should be fine..

63mako

If it is the original trans the first gear is a 3.42. The higher numerically the first gear the more stress on it and that would be the weakest T-10. The spread is real wide also so an engine with a wide powerband would be good and a cam with 112-114 LSA would be best match.The final drive ratio should be pretty good and your cruise RPM in 4th will be fine. Guess if it breaks you fix it or drop a richmond 5 speed with 1 to 1 5th gear in it.

Garys 68

I think only the f bodies got the 3.42 1st gear. Corvettes should have 2.88. They're typically rated in the mid 300's ft/lb range. So dont beat on it too hard.

DrainSurgeon77

If your trans has an Aluminum main case, you might want to change to the 904 iron main case... Crash

Augustus

Super T-10's are Very Tough trannys.

The 3.42 first gear tranny's from the 80-81 Z28's are probably not going to be the ones you want... It can't handle the torque load because of the highier first gear ratio and will strip the teeth.

The Cast Iron Case of the 80-81 ST-10's are very tough just the guts need to be inptutted with like a 2.52 first gear and so on.. Then you'll have the ultimate tranny. The Cast Iron case ST-10's have an Iron mid plate for reduced flex aswell that can add strength.

The aluminum 903 casting would be the best.. usually they came with 2.88 first gear and lower.. These tranny's I would grab in a heartbeat.

I have had it behind my Pontiac and previous Z28's and previous 73 Vette and these trannys can take a beating...

I also Love the gear ratios of the ST-10's better than my Muncie's

Right now I have an M22 behind me TA because I go crazy for the Gear Whine.. Love the noise.

c3sleeper

The one in the car is the aluminum case with the 2.88 first gear. I haven't planned on replacing the rear end until it either breaths it final breaths or the rear spring needs replaced ha. I'm planning on putting a centerforce dual friction clutch in any thoughts on that?

63mako

Right, 2.88 and 3.42 overlapped in 81. That gives you a 7.82 to 1 final drive ratio in first gear. It will feel ike a slug off the line. Best performance option is to upgrade to a richmond 5 speed or change rear gearing to a 3.55-3.73

Augustus

The 903 with 2.88 first gear is a good tranny, and i would worry about use it behind you motor.. One question I have is.. What kind of motor. Your pushing alot of power.. Is it a Big Block? With tonnes of Torque? If so good!!. You can compensate the lower rear end gear with the Big Torque of the motor.

Now if it's a High winding small block you might have a bit of issues off the line. and I agree you would want to have a higher rear gear to get that car moving.

Have a really good shifter with linkage & that Centerforce clutch will work just fine!

c3sleeper

The engine going in will be a 383 stroker with around 440 ft. pounds but im not sure what r.p.m. peak torque and horsepower are reached at yet as I havent received the actual dyno specs from the manufacturer yet as I just placed my order yesterday. The engine is supposed to ship within in a month so I've begin the process of labeling lines and wires. Tedious but well worth it in the end!!!

Garys 68

Good news is that if you drive hard, you're pushing both the trans and rear about equally to their limits. Which ever breaks first, you can upgrade.

mikejpss

I've done a few motor removal & installs in the 80 and 81 models. Last one was on my 80 with a new ZZ 4 crate install....

Best friend is :
masking tape
majic marker
tie wraps
zip lock bags: quart,gallon.

Take your time and label everything with masking tape.majic marker.
Use tie wraps to temporarily hold things back,etc.
Small parts in the zip locks- label the bags with the majic marker.
Its a piece of cake,just take your time.

resdoggie

This thread caught my attention. I have a '76 with a ST-10 close ratio M21. Any idea on the max TQ?

Garys 68

Direct from the source. They havn't changed the design much. Iron cases may be higher rated.
http://www.richmondgear.com/07pdfs/RG26.pdf

resdoggie

Thanks, Gary. 375 ft-lbs by the looks of it. Hope the design engineer applied a factor of safety.

MotorHead

Couple of things, the lower the first gear the less torque it will be rated at. An aluminum Super T10 with 2.88 first gear with no mid plate will handle 300RWHP and 330RWTQ, I have the dyno printouts for my original 355ci. 300RWHP is near 400HP Gross and 330RWTQ is also near or over 400TQ at the flywheel so it will handle a little more that the specs. say but engineers always put in a safety factor. When I was designing electronics I would put in at least 25%

As soon as I put the 550HP / 510 Tq 406ci motor in the tranny blew. I bought another one and it lasted a couple of days and it was toast. What happens is if you have enough torque and put your foot into it from say 2500RPM to 5500RPM the entire case starts to twist or distort.

Once this happens the gears inside get moved slightly out of line and enough to cause you to drive home in first gear. This is from my own personal experience and the reason I went to the Tremec TKO 600, so you are going to be at the limits of an aluminum T10

resdoggie

Thanks MH. It's going to be an interesting spring when she comes out from winter storage.

V8Ranger

I installed an aluminum case Super T-10 with 2.88 first in my 82, I love it but first is very sluggish. I also installed the dual friction Centerforce clutch - a couple of issues there. First is it vibrates at low RPM now, not very well balanced. Second, its a bit stiffer of a clutch pedal and I had problems with the stock linkage. Solution to the second issue in this thread:

http://forums.corvetteforum.com/c3-t...e-problem.html

Carl