Inside, the engine's greatest deviation from stock was a set oflower-compression pistons designed to provide about 10:1 compressionwith early small-chamber heads. Stock L72 engines featured 11:1compression, so we were giving up a full point of compression tofacilitate running on today's pump gas. Speed-Pro's forged No. 2300slugs handled the task. We'd make up the inevitable power deficitelsewhere. The rods are heavy-duty factory forgings, fully reconditionedand fitted with ARP bolts.