Subscribe to a magazine

Engine Dynoed

Back to article View Gallery
4 of 21
Kevin McClelland and John Wilson fit the 502 to Flowmaster's dyno and dressed it with a 750-cfm Holley double-pumper carb and 2-inch primary-tube Hedman headers, which were connected to 2 1/2-inch exhaust with Flowmaster 50-Series mufflers. We used a stock HEI from GM Performance Parts and Crane's FireWire spark-plug wires. The engine was broken in using Quaker State nondetergent 30W oil, which was changed to Quaker State 4x4 20W50 before any tests were started. We verified the catalog's power claims: The engine produced peaks of 446.7 hp at 5,250 rpm and 547.9 lb-ft of torque at 3,250 rpm.