I have a TH350, I usually use 4 speeds so it's a bit foreign. It works great in all gears forward but reverse just barely engages and THEN "POW!" It hits hard (sometimes hard enough to bark the 255's!) and works just fine... Once, it made a horrible screeching noise but hasn't since... It isn't improving but hasn't gotten any worse.

Is it shot, or is something just sticky? (the car sat for ~2 years) I hate to toss any money at this thing since the whole assembly is getting pulled and I'm using a 4 speed with it in the '68) but I'd like to keep using it until I have the car ready...I have a spare TH350 but I loathe swapping autos...but will if I really need to..