bj502

I've got a '95 502 EFI stock with Gill ex manifolds/SS risers thru Corsa silent choice. I picked up a pair of iron heads with 2.25 & 1.88 valves (I think). They look like new no rockers or studs. Numbers 12562934 & GM2 are on both heads along with F190 & F 240. The cam is from a HP 500 not sure if it was EFI or Carb. #975340 & 6209 are stamped on the end of the cam. What would these numbers mean? I'd like to wake up my engine some but not have to worry about reversion. Would these work or would it be a bad mix. ttfn