Well, it turns out the travel at the rocker arms are in fact the same. I did discover one (not the one in question) that was about 1/16" shy of the others, but I don't think that would be enough to cause a difference, and it could be due to the head casting.
This is good, in that I don't have to go through the ordeal of cam replacement (radiator, water pump. cover, manifold, on so on).
Thanks for your perspective and experience.
