360 heads ???

Just standard 360 heads, roughly '75-76 by the casting #. Open chamber, probably in the 65-72cc range. 1.88/1.60 valves. Pretty much the same as all of the other 360 heads out there until the "swirl port" design 308's that came out in the late eighties. Same as a J or X head, just smaller valves than the X's.

Open up the valves to 2.02/1.60 and they should flow enough for a 400 hp build with a good valve job.