A TH 350 is used to replace the Powerglide all the time, in different models & years etc.
You'll need to change out the converter & flywheel and the linkage is different too.
If you contact Larry/Novaman/Twisted 6, he will have all the exact numbers on that swap.
I think; it would be better to go with one of the 3 speed + OD automatics, rather the TH 350. The conversion is about the same and the 'end result' much better.
Good luck.