1979 Trans AM 6.6/ TH350 or TH400??

[nuclearkrieg]

Hello, just needed some help. My brother bought a 79 TA 6.6L with an auto matic but needs a new tranny. He doest know whether its an TH350 or TH 400. He says he has a 350 lined up to buy from a guy at work. I just wanted to know if you guys knew? I appreciate your guys' time. He tells me that the 400s are longer than the 350s. Anywho hope I gave enough Info.

John

[Morley]

'79's came with TH350's. The last T/A's with TH400's would have been the '74 455SD. The TH350 will be plenty strong for that engine, especially if it is the Olds 403 (6.6L). The 403 is a small block that isn't suited for HIGH HP due to the windowed main webs. Figure on getting about 450HP MAX out of it before things start to break.

[nuclearkrieg]

cool thank you for the info, greatly appreciate it!!

[MrPbody]

What Morely says is correct, but ALL '74 T/As got TH400, unless a manual... They had to delete TH400 (M40) '75-newer because it would not "fit" due to the catalytic converter.

Make sure the TH350 your brother has lined up is for Buick, Olds, Pontiac and Cadilac. A strictly "Chevy" bolt pttern won't fit the Old OR Pontiac engine.

Jim