i run amsoil saber mixed 80-1 for the last 3 years no problems just benifits! that hp stuff you're talking about i have used in my sled, it's also on nos. amsoil is by far the best in my opinon.
i just slide a long punch in from the oppisite side, tipped it to catch the edge of the bushing inside and drove it out. small scraches inside won't effect anything after all your going to put in a new bushing.
check the wiring harness, it's not unusal to have the wires short out inside the harness itself. when tested they test fine, put it back together and it won't work. strip it check each wire visually. good luck
pull the head, move the piston all the way down, if the opening to the transfer port is above the piston u don't have the right porting for your crank.