All really good thoughts and true. But I wasn't referring to built small valve heads, although that is certain a legit option. I want the high compression small valve heads that are also built. I already have basic small valve heads on the car. I could just take mine to the shop I guess. Drop $1000 and probably see a decent gain.
As for the expected compression. I used the 1969 46 heads at 68 cc. Admittedly I didn't do it correctly. I like the numbers oldsskol got way better.