are you running the engine in a buggy or a truck ? the reason i didnt suggest the pipe being the problem is i haven't ever really had that sort of problem running any pipe header combo (i have ran alot of different pipe/header combos). pipe/header doesn't really effect the throttle down effect but more over the way it builds its power . anyway , hope you figure it out topcat
monty
if you have a tight fitting body , try the rb header , its made for that and still gives you the length .