I picked up a pair of heads; 587 castings if foggy memory serves me right; I'm like the the 3rd or 4th owner (got them REAL inexpensive), don't know much about them other than they were radically angle milled and the chambers measure 45.5 cc. Pistons required new eye brows for valve clearance which I didn't think was such a big deal. Who ever did the machine work did a very nice job; all the bolt pockets were re-spot faced, they did a compensation cut on the intake face, so there haven't been any intake issues, and the cut the exhaust side also, no header issues.
I calculated out on my mean "Teen", stock rotator, these heads give me over 11 to 1 compression.
I'm glad I bought them.
