hey. as some of you know i am rebuilding my engine i have tore everything down. and tomarrow i am taking it to a machine shop to get the heads, Cranks shaft And Block resurfaced and cleaned up. but now i am kinda confused about my rebuild kit. i am ordering it from sumitt and some of you may know it comes with new pistons. but i was told that you should use your old pistons. is this true and if it not what size piston should i get in the rebuild kit. thanks alot for any info.