Cant scratch the retainers with a screwdrivers, there hard as nails, must be titainium, thats good news.

Well I beasured the pistons and the dome portion sits about .120 out of the hole while the top area above the valve reliefs sits at about .030 out. I saw a pictures of these pistons in stock form and they've definatelly been choped quite a bit.

Ok heres some new info, I cleaned up # 3 head chamber to cc the head and discovered that the chamber is fully smoothed and polished, real nice looking. Also I pulled an intake and exhaust valve, and they are definatelly longer then stock. They are Manley stailess valves with a 3/8 stem that tapers down by the valve head. The exhaust are 1.60 but I measured the intakes at a whopping 2.058!!!!!!!! My other J heads have stainless Miloden valves and they measure 2.023. So these 340 heads must be either 2.05 or 2.06, I've never seen such big valves in a small block. Also looks like under the valve in the bowl was ported as well. The valve guides feel tight and they had the positive seals. So it looks like the heads are in great shape.

So anyone know if these TRW 13:1(as stock) pistons can be cut down enough to get it down to 10.5:1 with a 62cc head? I found a set of replacements of the same piston, that the guy is willing to mill down for me, just dont know if they can be cut enough to get me where I need to be. Heres the head...