I had stock cylinders bored .60 over with Paul Turner National porting, stock crank, boyesen reeds, pro designs head w/ 20cc domes, advanced timing +4, 34mm PJ carbs, pro designs filter kit, paul turner midrange pipes, stock clutch, I am going to buy a serval 421 top end, +4 stroker crank, custom domes, pistons, HD clutch, currently run 50/50 pump gas and av gas. I wasnt sure if I needed new pipes or not the serval shines in the low to mid range so I thought the midrange pipes might be a good match but I am not sure. I was looking into either Pro circuit, Shearer or R2 pipes if mine dont work out. Also was wondering if a lockup clutch was necessary with the setup I plan on running?