[DiamondJim]

Anyone here know what length driveshaft I will need with a TH400 and a 12 bolt in my 78 grand Am? I will be running 1350 joints on both ends with a loop, is 3-1/2" steel the way to go or how about aluminum? Do I need 4"? What are some of you running? I know the longer the driveshaft the lower the suggested rpm, I imagine I will be spinning around 6000 max. Any help is appreciated. -Jim

[shotgun]

Mine is a th400 going to a 12 bolt out of a 68 Chevelle , center to center of the joints is 51 7/8".

The D/S 3.5" and my D/S guy says it can handle 1000hp, I am only hitting it with 625hp.

It is a heavy sucker at almost 25#, when/if the budget allows someday I will go aluminum(approx. 14#).

That's 10# of rotating mass removed.

Carbon fiber also looks neat , getting close to single digit weight , but the price.

[DiamondJim]

Originally Posted by shotgun

Mine is a th400 going to a 12 bolt out of a 68 Chevelle , center to center of the joints is 51 7/8".

The D/S 3.5" and my D/S guy says it can handle 1000hp, I am only hitting it with 625hp.

It is a heavy sucker at almost 25#, when/if the budget allows someday I will go aluminum(approx. 14#).

That's 10# of rotating mass removed.

Carbon fiber also looks neat , getting close to single digit weight , but the price.

Thanks for the info. -Jim

[DiamondJim]

Shotgun, if you are out there, do you think 50-5/8" center to center will work for me? Thanks -Jim

[455_regal]

I looked at all styles...I choose chromemoly because its suppose to be stronger and lighter then mild steel. some companies list a 3" at 800-1000 hp.