Virgin cores, no cracks, no crack repairs. 100 percent remanufactured with NEW valves 1.94/1.5 diameter. Hard seats for unleaded fuel, new guides. Resurfaced, fresh valve job, new seals. 500 lift z28 valve springs.64CC chamber size, these will fit all small block Chevy engines from 1955 and up (non accessory holes). One head is the 291 casting, the other is the 462. They are identical in chamber size, port volume and air flow. The item "462/291 DOUBLE HUMP CHEVY 327 CYLINDER HEADS, REBUILT PAIR UNLEADED FUEL PR" is in sale since Saturday, September 21, 2019. This item is in the category "eBay Motors\Parts & Accessories\Car & Truck Parts\Engines & Components\Cylinder Heads & Parts". The seller is "casl-patr" and is located in Wymore, Nebraska. This item can be shipped to United States.