Hey guys i have a Holley 500 on a built Ford 2300 w/ stock intake. Im using a 45pv, 74jets and 28 squirters. Im running race fuel mixed half-n-half with 93oct. and using a Holley "Blue" electric fuel pump at 5psi. Im problem is i've been fighting a "flutter" from 3500rpm and up. With his same set-up it would turn 7200rpm last year with no flutter. I've tried everything i know to do from changing fuel pumps, lowering fuel pressure, even changed the head. Thinking it may be a valve spring. I've even switched ing. systems from the Ford module style to the TCI ing. but still no difference.
Any help would be greatly appreciated.