SONNY'S SYMMETRICAL PORT 5" BORE SPACING MARINE / HIGH PERFORMANCE STREET
5" SYMMETRICAL PORT MARINE / HIGH PERFORMANCE STREET. At Sonny's all head porting is done in-house. We use a state of the art 5 axis CNC vertical machining center, which can produce precision work to programmed "blue print" specs. This unique cylinder head was designed by Sonny's for 500 + cu. in. engines. The intake runners are symmetrical and feature all good runners (runners that direct towards the middle of the cylinder). We offer the heads with Ductile seats and Ampco 45 replaceable drive-in step guides. These cylinder heads is to accommodate 5.000" bore center applications, including high performance street and unlimited Marine/Boat engines. Blocks and cranks can be purchased from Sonny's to match-up with this ultimate performance cylinder head.