jRoofgunner

Question: Can a TH350 (or 400) be put in a 65 Cutlass with a 330 engine and a floor mounted shift and would it be worth doing it?

joe_padavano

Yes and yes. The 2.52:1 first gear in the TH350 will significantly improve off the line performance as compared to the 1.76:1 first in the ST300. The TH350 is almost a direct bolt-in. The crossmember stays in the same place and the original driveshaft gets reused. The stock floor shifter will work as-is but you may not be able to manually access first gear. Shiftworks sells a conversion kit for the stock floor shifter to use it with a three speed automatic, including a new gear indicator lens for the console. The only small issue is the need to fabricate or adapt a bracket to route the kickdown cable to the carb throttle arm.

The TH400 is a little more work due to the need to relocate the crossmember and shorten the driveshaft. It isn't needed with a 330.