Help identify aluminum heads

Thanks for all the good info and help trying to figure out the engine combo. . . Assuming it is a 505 with 10.5-1 what kind of power is realistic the way it sits now with the 750 & smallish cam? . . Also is it common for a valve seal to need replacement on a setup that's approx 10yrs old with about 4k miles of easy street use ? . . Sorry for all the academic questions BTW