In need of some help.....
Thread Starter
2nd Gear
Joined: Jun 2005
Posts: 2
Likes: 0
In need of some help.....
Hi, I am new to the forum. I own a 74 vert and an 81. We have installed a new Dart 400 small block in the 81 along with a new 400 turbo hughs tranny. It had a worn 350 turbo in it but I decided to go with a new 400 since the motor is pushing around 500 hp (without the shot of nos). I was advised that I could just move the crossmember back to fit the new tranny in. Well, we got the motor & tranny in and realized that you can't move the crossmember back....at all. Thats where the seats are. This tranny is about 7 1/2 inches longer than the 350 was. I really do not want to pull this baby out again ship this 400 back and wait on a 350. I also do not want to make any expensive custom chassis mods. I guess my question is, is there any one else who has delt with this or is there a kit that someone produces to extend the crossmember to allow the 400 to fit? Thanks for your help!
Mitch
Mitch
Racer
Joined: Jun 2004
Posts: 322
Likes: 0
From: The Dirty, Dirty South
Is your cross member removable? If so, you could probably get a crossmember from an earlier vette and make it work. On my 77, there is a bracket on the x-member to mount the TH350. For the TH400, you just remove the bracket, I'm not familiar with the 81's, but an older vette x-member may be what you need.
Instructor
Joined: Jun 2005
Posts: 142
Likes: 15
From: Austin TX
If those suggestions don't work, post a note here and I'll see what my mechanic has to say. I replaced my 350 with a 700R4 and all sorts of things had to be changed, including the length of the drive shaft.
Or I could look under my car and see if anything obvious was done. I know for sure I have the original crossmember, so that wasn't replaced.
Or I could look under my car and see if anything obvious was done. I know for sure I have the original crossmember, so that wasn't replaced.
Thread Starter
2nd Gear
Joined: Jun 2005
Posts: 2
Likes: 0
Thanks for the ideas. The cross member unbolts and is removable. Does anyone know if an older cross member would fit? Also, the emergency brake set up might be different on an older one....not sure about this. I already planned on having a custom driveshaft made. Thanks again guys! 
