302 casting swirl port heads

So, not to hijack the thread and it is related to the topic (or at least the title of this thread.) :)

Is there a way to identify these heads if I were to go to a junk yard and try to get a pair? I assume that "302" is the casting number...if so is it actually stamped on the head somewhere? I know they came on 1986-90(?) 318s, but I'm so uneducated about this stuff I'm not sure if I could tell the difference between a 318 and a 360.