Ive had the z28 since i was 16 and drove the crap out of it for the first two year I had it. Then parked it for a few year while I went to school. After school i swaped the old 305 with a 73 350 block. And while fine tuning the motor the auto trany wasn't shifting gears while in overdrive so I have decided to go ahead and change it over to manual. Need help with transmission preferences that line up with the shifter plate on the factory console in the car.

 

T5 is the easiest, T-10 was offered in '82, T56 is the current thing, there's Tremec's TKO500 / TKO600, Richmond's 4+1 has been done, there's a 6-speed version of that called the ROD, for Richmond OverDrive, They also have a Street -speed that might install similarly, various others have been attempted with generally sub-par results, from Nissan Z32 turbo 5speeds and Toyota Supra turbo, to various GM truck transmissions. For a mild 350 for daily street use, the T5 from any '88-'92 LB9 third gen will be fine. Carbureted 350s generally can't take full advantage of a T56 with the 2.66 / 0.50 gears, T-10s have no OD.

 

Well I've got a 350 bored .30 over with aluminum 64 cc heads, a .525 lift cam fueled by a 750 Holley vacuum secondary. Don't know specs yet but I'm worried the t5 can't handle it long.

 

I've had a T5 behind a 350 HO (350/330) for a number of years without issue. That said, I never hotrod the car. If you plan on spirited or very spirited driving, the T5's time will be limited.

JamesC

 

And that's exactly why you won't get any use out of the T56's sixth gear.