i just accquire a 460 which had some smog or emisson stuff which i removed but i found there was a hole in back of the head for a tube for smog or emission... i m not running anything what shd i do with those hole?
take 1\4 npt tap thread use oil galley plug
all you need is a soft plug. go to napa and look it up the size.
I had a brain fart on that post. take weld the pipe closed and bolt them on.