trans replacemnt

[jester]

'm currently restoring a 66 impala rag top.(same as 65) I have decided to install a 454 with a 400 trans. The car currently has a 327 matched to a powerglide. My question is , will I need to modify the trans cross member for the 400 to fit properly?
I know someone here must have made the swap.
Any information would be helpful.

[models916]

crossmember will fit the trans mount, but will most likely have to move rearward some. Usually holes already drilled by the factory in the frame. Just slide it back. Will need a new front yoke and shortened driveshaft. Easy fit as the factory used big blocks with t400 in that car. I think the frame mounts are lower, but it might just be the motor mounts for the big block are thinner.

[jester]

Thanks for the info. I need to pull the from mounts before I send it to the bone yard. Thanks again.

[jim_ss409]

The yoke for the 400 is likely to take a larger U joint than the stock driveshaft. But you can get an adaptor U joint from a driveline shop, or Lakewood Industries, the scattershield people. A new yoke for a 400, 32 spline I think :scratch is pretty expensive if you've got to buy one new but you can get one from the wrecking yard for alot less. They are common in GM powered trucks, usually 3/4 ton and up. Most cube vans have the size you'd need.