after you go through the heads and measure your clearances...what about doing a simple 1.7 rocker swap. Something like harland sharp makes a bolt on kit that once you make sure your push rods are the correct length is just a bolt on piece.
Bigger rockers is a great idea for him. To put into perspective, I have a 360 mag with .534 lift and because of lifter geometry I have .500 dynamic valve lift. The cam in his engine is mild in terms of lift and 1.7 rockers would be a quick fix , not too expensive , more accurate and mostly cheaper than a new cam. Figure a new cam is 350 plus a 100 oil pump drive. Although you may need new pushrods in both scenarios . Do you like the power band of that cam? Do your heads use factory rockers?
