When you hear about the deck height, it's usually more of a guideline than an actual number unless your machinist cuts the deck to your specs. Our rotating assembly added up to exactly 8.200 inches, which is theoretically the same as the stock 302 deck. Our pistons were 0.035 in the hole in the original 302 block because of the factory deck variance. The CNC deck surface on the Summit Block put the same piston 0.005 in the hole, right where it needs to be. Deck height also has a big effect on compression ratio. The 0.030-inch-tighter deck clearance adds more than half a point of compression.