Sounds like your going to get more experience. Did you put a pressure gauge on it at first, and is it the same as now. I still think those pressures are to low. I rebuilt a 200 4r and my pressures are above 175 up to 225. Its possible that you may of left to much clearance in the clutch pack, or bad seal.
You should of gotten some pressure rise when the rpm's rose. That is why you could have a pump problem also