I use these on my 10.3:1 340 .025 above deck, RHS Indy X closed chamber heads. My block surface was to rough for cometics and these composites are less expensive and work. SCE Pro Seal Composite Head Gaskets 569096
I will give them a good look once I nail down the numbers. Seems like Cometic is behind the curve on delivery too. Shouldn't matter, the car will be in the shop for a good part of the summer.