69MustangCoupe393cid

So I did a search and didn't find much info on this so here it is. I just did 4.10's and now that I'm turning more RPM's and my clutch will probably be taking a crap soon (car has 84k on the factory clutch/TOB) I was thinking T-56.

I like the gear ratios from the 97+ Camaro/Firebird (I think it was those years... whatever years had the following ratios... 2.66, 1.78, 1.30, 1.00, .74, .50 ) and I was wondering what it takes to do a swap like this if it's even possible from one of those cars.

I know shorter drive shaft and a different clutch due to 26 spline with a cobra cross member, but will the bell housing have to be changed or will it bolt to a mod motor or can it not even be changed? What else would have to be changed an or does anyone have a list as to what has to be done? Will all electronics plug in and will it fit right etc. Any info will help as I pretty much know nothing about what really has to be done. I saw Jazzers thread, but I'm wondering if anyone has a list and if/how the GM trans is different.

TIA

Jazzer The Cat

The trans should be the same, but the BH differs on a GM.

Jazzer

69MustangCoupe393cid

Thanks jazzer. Do you have a list of all the parts needed to swap over to the t56?

Jazzer The Cat

I purchased my trans new, along with the BH and cross-member from Modern Driveline. You already saw my swap thread and everything I had to do, is all written up in there

Jazzer

69MustangCoupe393cid

Reading your thread Jazzer I think you made the right choice in the gear ratios for sure. The GM trans is going to almost completely ruin the point in me having 4.10's because of how high the gearing is. Yeah OD is nice, but the rest of the gearing makes the car act almost as if it had only 3.55's with my stock trans.

Bang for the buck it's looking like swapping to a 3650 with a .62 OD gear is going to make more sense for me. The T-56 you have will certainly be better, but for the money it's probably not worth it for me for the little extra speed I'll get out of it. I don't mind the jump from 4th to 5th and it's going to save me a bunch of money. Guess I'll wait for the day I buy a terminator to have a t-56.

Bman2000

my 2 cents. first off im not sure the gm tranny can swap....i mean without changing almost everything on it. bh and tail shaft housing are different, and plugs may be too. In any case, i swapped to one out of a cobra i believe. The swap is simple, and i did it for the close ratio gears, i have 3.90s. so i run almost factory rpm at speed .62od? i cant remember. Either way i just want to say this, i put it in cuz i thought it would make a difference in accel due to better gear spacing. Well my car isnt modified enough i guess, it actually slowed me down due to the extra weight and drag. might be worth it for road racing but drag racing, its a loss over a 5 speed. i have a turbo fox friend that swapped and he lost a few tenths in the quarter.

69MustangCoupe393cid

That's why I'm sticking with the 3650. The T-56 ratios need at least 4.10's. Basically your car is acting as though it has almost stock gears because you lost the tall gears down low. The t-56 is ok in a higher HP car because it can make use of the longer gears. My car doesn't have enough power to rip tires off like crazy so I need the gearing to help out.

Bpohlman13

Hmm why did my posts get deleted? Thats weird. Oh well. The 3650 is probably best for you if you dont plan on making high power levels. Only reason I got the t56 magnum is because I wanted a 6 speed and needed to handle the power when i put my new engine in my car.

69MustangCoupe393cid

ah. Ok didn't notice the build. That should be a nice setup. The stock trans would rip through the gears too fast and make it pointless to use first and second gear as they would result in tire smoke.

Bman2000

actually it doesnt act like a stock tranny, the gear spacing was much better to keep this motor in the power band thats why i went with 3.90s and the t-56 because now when i shift at 5800 its drops right on peak tq around 4k-4200 so the hope was that i would keep the car moving better because when i shifted i wouldnt be going all the way down to 3500or so which is what the factory stuff does. the problem was just the weight and parasitic loss. so for a road track car, it probebly would pick up time, but as a drag car it lost some.