I have a set of the stepped washers new, ARP ones, but I'd be installing some ARP head bolts too. I don't see the sense in just taking the heads off the 351 and slapping them back on your car personally but if that is all you have I guess. Why did you blow the head gaskets? What are the mods? I have installed a few different KB's on 5.0 cars and one of them blew the headgaskets and he didn't listen to me about timing.