I have a restored 72 Chevy 350 with a TH 350 transmission. It has had a recent shifting problem where it will either not shift to a higher gear unless it is at a very high rpm or it will downshift prematurely. I checked the vacuum line from the engine and that seems to be working. Are there any other areas where I could check.

Thanks,
Tom

sounds like your low on tranny fluid

sounds like maybe your modulator valve is bad..have you replaced lately?

unhook the kick down cable from the carb, then drive it and see if it shifts right.

My car also had the same problem when my fluid was a low. Hopefully It's something so simple.