Transmission swap questions

[Sammy Boy 0]

I've got a 1970 T-37 Tempest, which i recently learned through PHS is nowhere near original, so ive decided to swap the motor from a 350 2v to a 455, the 455 i purchased came with a TH400 attached, but is from a 1970 bonneville. The T-37 as of now has a TH350, So I guess my question would be what would need to be changed, if anything, to put the bonneville TH400 into the Tempest or would the TH350 handle the stock 455?

 

Thanks, Sam

[TWO LANE BLACK TOP 95 2 Vehicles]

 Only thing you might have to change is the location of the crssmember either forward or backward....It's very Possible could already have the frame predrilled from the factory to relocate it...Also the transmission yoke will have to be changed too...Possibly the length of the driveshaft depending on which tailshaft the TH 400 has...Will also have to have the electric kickdown switch...As the TH 350 kickdown is a mechanical cable...Should be a pretty straight forward swap.....

Edited October 19, 2018 by TWO LANE BLACK TOP

[Frosty 922 3 Vehicles]

11 hours ago, TWO LANE BLACK TOP said:

 Only thing you might have to change is the location of the crossmember either forward or backward....It's very Possible could already have the frame predrilled from the factory to relocate it...Also the transmission yoke will have to be changed too...Possibly the length of the driveshaft depending on which tailshaft the TH 400 has...Will also have to have the electric kickdown switch...As the TH 350 kickdown is a mechanical cable...Should be a pretty straight forward swap.....

Nice thing is the electronic kickdown switch and the rest of the parts are readily available from most of the A-body and performance catalogs. 

When I swapped Lucy from a TH350 to a TH400, I didn't have to drill the holes for the TH400, they were already predrilled on my car. However, I did have to get a longer emergency brake cable made, which I got from Inline Tube, who are local to me. 

One suggestion, depending on what you do with your car. I wish I had gotten a BOP-bolt pattern TH200 4R (overdrive) given all the highway miles I drive with Lucy. You can build them up to hold the power of a 455. If a GSX Grand National can run a TH200 4R, so can Lucy!