[LaVelle]

Anyone use a long output T400 in a high power racing application?

With the short output T400 I have in the car now my driveshaft length is 59 1/2-60" long and critical speed is an issue.
A long output would shorten the driveshaft length down to where critical speed wouldn't be an issue anymore.
So will a long output shaft T400 handle over 700lbs of torque in a heavy car?

 

[bracketchev1221]

I don't remember what the length of mine was exactly but I used a 4" aluminum Mark Williams driveshaft in my 70, and had no issues for 15 years going to 7800 in the lights. When I called Mark Williams, they told me it was either aluminum or carbon fiber to prevent the critical speed issue.

 

[600renegade]

Not a TH400, but I do use a long tail TH350 behind a strong 327 in the truck in my avatar.... have done many passes on it and have not had any problems (knock on wood)....

 

[LaVelle]

I don't remember what the length of mine was exactly but I used a 4" aluminum Mark Williams driveshaft in my 70, and had no issues for 15 years going to 7800 in the lights. When I called Mark Williams, they told me it was either aluminum or carbon fiber to prevent the critical speed issue.

4" is what everybody recommends. Only issue with that is putting a 4" shaft in my car is its like fitting a semi down a bike path.

 

[LaVelle]

Not a TH400, but I do use a long tail TH350 behind a strong 327 in the truck in my avatar.... have done many passes on it and have not had any problems (knock on wood)....

Cool truck. I've seen a few long 350's used here and there, but not at the power levels I'll be subjecting the T400 too.
The Mike Lewis 532 I have at 700 lbs. of torque and slicks will find weak drivetrain links in a quick hurry.( I just don't want to find out the hard way.)