Hello everyone, I've recently rebuilt a th350 that I've put back into a 71 c20 behind a 307 after the sprag(?) in the rear exploded (but went into gear just fine before)...I've cycled through the gears, but there is zero movement in the wheels until the rmps have upped a good bit, and even then we could only get them to turn in drive and slightly in L1. We've checked fluid, adding when needed (rarely) while it was running, but the level wouldn't go down. I've looked up the problem, but I'm getting mixed responses. It sounds to me like it may be the pump, but we took the trans out a second time to check this and couldn't spot anything obvious, as well as making sure the TC (new) was mounted correctly. I haven't disconnected the cooler lines to check for flow, but a buddy of mine seems convinced it's the pump. I need to know if buying a pump would be a good route to go, or if I've screwed this thing up so astronomically I need to get a new one. Trying to avoid shops around here... I apologize for any ignorance, I'm a newbie when it comes to transmissons (first project truck, first trans rebuild), but constructive criticism is preferred!