700r4 help

[K Dubb]

I have the 7.3 454 in my 77. Im switchin the stock th400 to the 700r4. What I need to know is do i have shortin the drive shaft....by how much?...AND do i have to F around with any cross members?

Thx Kevin

[magnethead]

what is the 700R4 out of? Do you intend on towing anything?

If the answers are "a pre-87 vehicle" and "yes" in that order, just make sure you have something real thick between the transmission and the floorboard, otherwise you may be in the hospital with a chunk of planetary gear stuck in your leg.

yes you need a longer DS. Yes you must move the tranny X-member

[K Dubb]

All race... all i have is the case to the trans i have a guy thats going to rebuild it with a shift.

[magnethead]

ok good. The pre-86 700's were prone (i'm not sure prone is a good word..inevitable maybe?) to detonating when put between a high torque motor and a heavy load. The 400 is actually longer than the 700 i believe.

http://72.14.209.104/search?q=cache:...s&ct=clnk&cd=3

http://www.smokemup.com/tech/700r4.php

couldn't find much else, the TH350-700R is a more common conversion.

[K Dubb]

As far as the 700 not being strong Its not a problem theres ppl runing 11's with a 700 so......any idea about the crossmembers?

[magnethead]

Not sure on the X-member. The spline counts for the 400 and 700 are different, so you need a new yoke.

http://forums.corvetteforum.com/showthread.php?t=237853

[bigblock73]

Yes, you will have to move the cross member and drill new mounting holes for it to bolt up.