All I can remember on em is the intake ports are higher so for a B you would need an RB intake (evidently the height increase is exactly the difference in heights) & as you know head/block milling and OE heights/head gasket thicknesses will require slight adjustments from that when mocking up to check. EDIT If you need spacers for a B intake get ahold of Jerry at SD Concepts a board sponsor here. He made some for me for a SB & they were works of art (dead on perfect), for reasonable money too