going to rebuild shee and need new pistons, what is a better choice for a motor that has porting set up for mostly drag racing . i know they have two versions of pro lights one a little lighter than the other but is thier a real difference between the two in power for the extra cash?second im getting a extended swingarm and cant make up mind on plus 4 or 6 length i race mostly in sand and was wanting to know if a +4 would be enough to keep front end down.if a +6 is what i need does any one know whatlength chain i would need.thanks. sorry long post