You are looking at a pair of 1968 Chevy big block oval port cylinder heads. They are cast # 3917215. The dates do not match. They are H27 & D28. This cast # is correct for the following:

Late 67 & 68 full size Chevy, Chevelle and Camaro 396 325 / 350 HP

Late 67 & 68 full size Chevy and Corvette 427 385 / 390 / 400 HP

These were removed from a running 396 3 years ago and replaced with aluminum. These heads are cores for rebuilding. They will need new valves, valve guides, etc. They have never been rebuilt or hot rodded. These should be good, safe, crack free cores. You get then the way you see pictured. Was never blown up.