Not sure what I have here, but in a trade I acquired shaft rockers,lifters,pushrods, heads with matching pistons from a  sprintcar engine, the heads are   2- Alan Johnson 9952-B-280- 01 and 02,and    2-  0008-A-280  heads,  have guy forbrook spec. also stamped  on them   Let me know if that is something of interest to you. Dan 507-380-2283