They are World Racing Products 305 heads #042650. 1.940 intake valve, 1.5 exhaust. NO polishing, grinding or welding has ever been done to them. They are complete with valves & springs. We ran these heads for 15 or so nights with a spec sprint car organization that has now gone to RaceSaver rules before the start of this season so we can no longer run them. Do not know the date of the casting