360 Mild Build Questions

Locomotion said
They worked on the engine they came off of. But there is a chance that one or both heads may have been replaced at some point during its lifetime. It wouldn't hurt to check chamber cc's, valve heights & intake valve size along with the usual magnaflux for cracks. I don't know what a normal OEM date code "spread" would be between original head castings but check that for more clues.

I don't think they were ever on the '74 short block I bought. I think those heads got tossed. The J head looks identical to the U head, the U head is bare so I'll put new valves, springs, etc. on both heads. I'm also planning to go with some adjustable rockers, I had that set up on a '68 Barracuda I had over 20 years ago and it was a fun, lively car. Wish I still had it.