scratchy , that plug is 1/8-27NPT , one of the heads I had had that same plug , the other head was NOS. I got them from Paul Rossi back in the 80's , they had big valves and were ported some.
any idea what the plug is there for????
I will try an AR24 plug,didnt know they had a race plug,may be good with the mallory duel points dist I have for mine
looking in the daylight now,I see only the driver side head has the 1/8" plug. and the end core plugs are smaller than what is in the pics posted by Lee.
they have a bigger machined boss area where the 1/8" plug is. both my heads have the bigger machined boss area but only one plug.
I think one could tell the diff in the two 452 castings by the size of the end core plug like was mentioned about the 1 and 2 marks cast on the ends
I would think the peanut plug with extra cooling ports would be more of a MH/HD/truck thing and why some guys have not run across it on all the yrs of working on muscle cars.
now that they have been out of production since 78(80 in the MH/HD chassis) it is showing up more and more as they get saved and transplanted into other projects. and we see just how much odd things/changes come down the line.
