Will has his own cam grinds made for him, the SBC cam is a great cam and there was head room left for more lift on better heads and using a full roller 1.7 rocker completes the package. With stock heads using a decent sized cam with rockers is not going to work because there isnt enough clearance between the retainer and the valve seal. On ported or reworked heads either the guides get turned down for more clearance or LSx style valves are used, what ZZP uses, and this gives plenty of clearance between the retainer and valve seal.
