14 With the short-block more or less complete, let's have a look at the heads. Mike Ware likes to stick with 5.7 castings on his Gen III Hemi long-block combos, and not just because they are the most available and affordable. More importantly, Mike feels that port volume and cross section on the rarer and pricier 6.1 or 6.4 heads are so large as to hinder low-lift flow velocity. That said, he did CNC port our factory 5.7 castings, but purposely kept volumes smaller than on 6.1 heads to promote velocity and, therefore, torque. He also enlarged the intake valve seat to 2.100-inch diameter, allowing use of 6.1-spec 2.08-inch Manley valves (the factory 5.7 intake valve is a smallish 2 inches). Exhaust valves are also upsized from the factory's 1.55 inches to 1.60 (which does not require seat mods).