Hi im redoing the topend on my Honda 300ex and going to do magnum namura big bore kit. 330cc 80 mm piston. it comes with a new jug, with sleve, piston, rings, wrist pin, circlips and gaskets. is this a good brand? Now to the need help part, will my stock oem 300ex head with stockevery thing cam, vales, and springs work this this new jug. And perform good as in power with the big bore kit installed? its 250$. Just verify help it is that I need to know will my stock head vales and spring with stock cam work this big bore kit without the piston slapping the valves? And not be choked out and not have good? or will I have to get bigger valves new cam and valve springs???? IM IN ERGANT NEED OF KNOWING THANKS IN ADVANCE!!!

 

Most Bore kits is a straight forward bore increase only, same jug just a bigger sleeve and piston in it. The kit may even have instructions or you can contact their web site.