Best wishes for you and your (how old?) son with a 360. Hopefully he is responsible with power (see Mustang crashing videos)
My low-level recommendation (KISS) is to either recondition the cylinder heads, or buy the chinese Speedpro/Speedmaster aluminum heads assembled & have them checked out at a machine shop.
First option, call up summit,
get valve spring recommendations,
the giant c clamp removal/installation tool ($100),
remove valve springs and retainers
(AND KEEP TRACK WHICH VALVE/SPRING/RETAINER GOES WITH WHICH HOLE ON WHICH HEAD),
bring the heads (bare) to the machine shop, have the shop perform a valve job,
ask about hardened seats, ask about valve condition,
have the shop verify valve spring retainers or replace them,
install valve seals (Viton??), and
either they assemble the heads for you or you take the clamp are reassemble them yourself after one more extra cleaning, drying, and then lubrication.
after these two choices, and if unlucky, during these choices, cylinder head options can be expensive.
keep it simple sir!
Another option is the dodge 318 (1980's) '302' cylinder heads refreshened-without porting they would govern the rpm's of your son's driving due to less air flow but increase torque with the smaller, closed chamber, cylinder head. Mopar official would port them for you for more air flow.
the 273 cylinder heads MIGHT not bolt up to the later LA if it is an early enough engine as I understand the members here on FABO SBM
