I had the same problem when I put a 235 in my 1949 GMC 3/4 ton. The kit that I ordered had pressure plate, throw out bearing and clutch for 1949. The clutch would not release when all was installed. Finally ordered just the clutch disc for a 1962 chevy which is where the the 235 started. The hub for the clutch disc on the 1962 was shorter front to back than the 1949 clutch disc and apparently was causing the problem. The hub on the 1949 clutch disc was too long and put all in a bind when I bolted the pressure plate to the flywheel. I put the later model clutch disc in and everything works fine now. The truck is not on the street, but all seems to work well and I can run through the gears, start and stop with no problems. You may want to check with more experienced mechanics, but that seems to have cured my problems. If you still have the old clutch and pressure plate from your original, check it against a clutch for the model year of your engine.
