Y'all were going for the Flat Tappet Heads and these were stated for the Hydraulic Roller which is the kind of Magnum block the shop i'm gonna have do my prep work told me to get, I couldn't get ahold of the guy I had talked with in Va about the heads when I was ready to pull the plug and purchase on BF but spoke with him the next day and asked if I F-ed Up, he said nah, if anything the spring pockets might be deeper but they could be shimmed. No big deal