I went there and saw them. Those are the cleanest GMC blocks I have ever seen. That is a good cleaning system. I've never seen pistons like those. The head puzzles me. I would not think you could grind the 302 chamber to that shape yet there it is. I wonder if there was welding involved? They did a lit of fill and mill on the Chevy heads.
My 270 has small ports and even the least desirable of the 4 GMC heads. It works just fine. So much of the lore is about race motors. I talked to Bill Fisher on the phone once and he told me just what he said in his book that the small ports are actually better for the street, even for a hot street motor. He made quite a deal offing honest of what the engine will TRULY be expected to do.
You'd be days trying to get those pictures on here.
