The 12363390 is an aluminim oval port "Bow Tie Performance" series. 2.25/1.88 valves with 11/32 stem.
Dual springs, 1.514 od, 140# at 1.94, 1.20 solid height, and 368 lbs per inch (same spring used an all 502ZZ engines).
290 intake runner
110 exhaust runner
110 semi open chamber combustion chamber
Great mid range performance.
Dave
P.S. Lose the 5.00 gear, it's too much.