The HP Billet block has water between the cylinder bores and therefore capable of a 4.500” bore diameter. It is dressed with all 4-bolt main caps, however #2, #3 and #4 caps are machined billet 8620 steel and #1 and #5 caps are nodular cast iron. The HP Billet block has a standard valley tray, hardened fasteners, and a cam tunnel machined to 2.50”.
