i also have an h23a1 with a spun bearing so i want to rebuild it. does anyone have any good ideas of what i should do to it. i was thinking bore it port and polish 10:1 pistons rods cams valves springs keepers retainers cam gears and a new 3 exhaust. but that is just my idea. enlighten me as to anything elsei could do. but there is one thing i want to run all motor.