stick to 250-260bhp mate when you start going above that its gets silly and the power from 1st to 3rd becomes useless pluss it will be more reliable!! a good honest 250bhp zvh will do impressive 1/4 miles and there a machine an half at that mate, maybe start looking into transmission etc getting all the power to the floor instead of wasting power and money! am sticking to 260 when mines done, but who honestly knows the limit of zetec rods.... answer: Depends how you drive SIMPLE!