Ok it's been awhile since I've been on here. I have to rebuild my engine my self I was wanting to pay someone else to do it but you know how stuff gets in the way. Any who I have just taken off my intake and heads. But my question is if my lifters are still good and the pistons slide back and forth like they are suppose to. Do I need to worry about the cam and crank? My motor is a 390 4bbl and has 81,000 original miles.