The pistons are JE products, typical for Pontiacs, except for the thin .043-inch top and second rings, and 3mm oil ring set. The top ring had to be placed .270 inch down from the top of the piston to clear the factory notch at the top of the cylinder bore, and Mike knows there's more efficiency hiding here if he can get the ring closer to the piston deck. Pin diameter was .990 inch, and is a bushed, full-floating design. The tapered dish works well with smaller chambers, and the non-dished part of the piston comes within .030 of the cylinder head deck at TDC for good quench.
The roof has been raised, the cross-sectional area fine-tuned, and obviously the floors have been filled with epoxy. It's not hard to see how an amateur could quickly get into trouble without knowing how to properly design an intake port! Check the accompanying chart (p. 76) for the flow numbers on these heads, and know that when it comes to making power in the 2,500-6,500-rpm range street enthusiasts crave, port velocity becomes just as important (if not more) than port volume. Small, zippy ports make more power across a wide rpm band than big, lazy ones. The key is to get the right amount of port flow at the highest possible velocity at a given lift point, and it should be obvious these heads can be fine-tuned to work well on almost any Pontiac V-8!
The Kauffman head runs an offset rocker to allow for the wider port. This design alteration moves the pushrod over a bit to make more room for the intake port. An offset rocker becomes a requirement, and T&D Performance makes them. The intake rocker is offset .700 inch, while the exhaust rocker is offset .080 inch. This means the pushrods will be angled, which isn't optimal, but Pontiac guys have been running them in this configuration for several years without problems.
The small 56cc chambers encourage efficient burn characteristics, especially when teamed with a well-designed dished piston to achieve the desired compression ratio. The Challenge rules limit compression to 10.5:1, and after all the final measurements were done, Semchee found himself at 10.2:1 with insufficient time to have the heads milled and still be able to get the engine built, broken in, and to the Challenge on time. The efficient KRE chamber made best power with only 30 degrees of ignition advance! With the bump up to 10.5:1, it might be even less.