Powerglide/TH350

[oldguy64malibu]

I have the 64 Malibu Convert with a stock 283 and Powerglide.
The car is new to me and now that I have put some miles on it I like the engine but the two speed is prehistoric. Additionally the tailshaft bushing is worn allowing a slight trans fluid leak. The Th350 from what I read is a direct swap. Th ecar has a columm shift which I want to keep along with the bench seat. Does the 350 trans require a different columm shift indicator since it is a three speed ?
I have forgotten what a great engine the 283 is and it is all I will need for beach and ice cream trips. Gas mileage is horrendous, even after a tune-up.
Thanks.