The stock rod is junk, and it could break. You'll need to beef up your valve springs if you run a new cam. The type of can will determine what size springs to use. If you go up to 26lb springs, you might consider new valves and keepers. Going fast is expensive. Your valves will probably float before 6000 RPM's with the stock springs. I changed my stock rod when I did the flywheel and added the new head.