auto is good. traction issues with stick and allot more breakage. bigger carb will help if jetted correctley. if not will hurt power. performer rpm is good on fe with head & intake ports matched. no need to fine polish on unleaded. fe's can wind pretty good. just let it breath. I have moved to lower rpm strokers for more torgue to pull the c-6 better. aftermarket heads are amazing depending on budget. I also have a 410fe if you know anyone who needs one. I like no smaller than 3 in pipes with balance tube close to the motor. helps on fe to get the exhaust out.