A trick for installing impeller- I place a tie wrap around the blades and tighten it and then place it in my freezer overnight. Just before installing I cut off the tie wrap and the impeller blades remain squished as they are frozen. It slips in easier and they thaw and spread out in a very brief time.
Very interesting approach Steve! I for one, just did impellers on my 427s and my method was to coat everything in dish soap, fold over the impeller fingers at the cam plate, then while turning the impeller shaft, gently press the impeller into the housing until the keyway aligns, then POP its in. Another thing I like is that the dish soap is not like a lubricant that could get stuck in the system somewhere. Also, when I fired them up and looked over the transom I was able to confirm prime by observing a brief bubble bath!