Building friends motor aka "what will it make"

Friend I play baseball with has a 67 dart and wants me to build his 360 so I will ask what will this make.

360 kb 107 pistons 62cc heads= 10.9.79 comp 64cc- 10.7 comp .038 gasket
Ported RHS heads from IMM so 280@500
solid FT 251/260 @.050 on a 107lca and lift is like 560's with 1.6 rockers.
Air gap or single plain intake
3in Exhaust with X pipe
He is not sure on the headers so 1 5/8 cheapies for now
750 proform DP
3.91 gears
4k stall

What kind of power do you think? I told him to try the comp xs282s like I have, but I also showed him this cam because brian said it would work well