Originally Posted by cobalt327
Seems there were ST400's used in '64 Rivieras (guy says he drove one for 13 years, even describes the peculiar shifting of the ST400). Maybe Buick used both, but the TH400 wasn't mentioned.
"Super Turbine 400" was simply Buick's marketing name for the TH400 when first released in the 1964 model year. The other available automatic (the two speed used in the A-body) was called the Super Turbine 300. Rest assured that the original trans in the 64 Riv was a TH400. I have seen these personally, with the unique bellhousing. It's a TH400.