Don't get it right, just get it running. 85 318 roller

remember, you're building a stock motor you don't need to get wild or be fussy with the heads.

having your stuff checked by a machine shop isn't a bad idea but just go into it knowing that it's likely to snowball with needing things and stuffs.

the benefit you have is that because the motor is "new enough" and popular there are options-- both aftermarket and reman. for instance, fully assembled reman heads with warranty run 250~350