About 10 years ago I bought out a retired GM engineer who had a passion for the 60 degree. I got an aluminum block, gen 1 Alum heads, prototype intake manifold... acres of parts. These were in the mix. They are for 2.8 Iron heads. They are full roller, tip and needle bearing mount. 12 rockers in all, what you see is what you get, you'd need poly locks and nuts.
They are 1 off's with no part numbers and very well made
$150 + Ship
The original post I made about the prototype parts is around here somewhere.....