Big bore without porting will create less power than stock, If I were you just send the hole top to eric gorr and bolt and go. as for v force i don't know i have a boyesen rad valve on my bike and I don't have any complaints. and replating is much better than a sleeve. They have to bore replate, port, and cut the power valve, and head work on a big bore but you need to check with eric gorr on your bike cause some bikes have to have case mods, cant complain with my 144 kit I got from him got back in 2 1/2 weeks and looked great and he will help you with any questions you have, Top notch in my book