thanks,this is the kind of info I'm looking for.The books I got don't have much Info on small displacement engines.I would like to keep the same heads( 3884502)closed chamber small valve power packs.Can these be re- worked with unleaded seats and slightly larger valves to make them more efficient without costing more than I should spend($300- $400)?.I can do some minor porting& clean-up myself.What about that power glide ,will a stock rebuild do it or should I put a heavy duty kit in it?It runs fine now should I leave it and see if it gives me trouble first?