The design engineer of the '420' told me that the 'AB' was an update of the '598'. Basically they eliminated material that was consistantly removed from the porting process. So the original '598' is not necessarily a lesser manifold than the '598AB'. As usual, nice work Laverne.
I'd have to check again on the PN# but a buddy is using an angle milled Bowtie intake on his 15* SBC with good results.(850HP)Is this a 15 or 18 deg. head SBC? Can you give us any details or is this a grudge/secret build?
