They would probably work without the extra bolts but the holes are there use the bolts. The CPs look like the Felpro printoseal, did the Cometics come from Summit ? Can you exchange them for the Felpros ?

I got them from summit there getting sent back. I was hoping to have the boat going for the weekend. I'm going to order the CP ones.

I got the Mr Gasket ones last time and they are really nice, lots of meat around the water ports. I see you are using the Cometic head gaskets, were both the heads and block machined to the correct spec? My machine shop guy would not let me use them because the block deck had not been machined to the proper spec.

The block has been decked before but not between me changing head gaskets. The Cometics are the same thickness compressed as the FEL-PRO ones. I guess I'm confused on what spec your engine builder was referencing? Flatness?

There is a smoothness spec (RA- roughness average) that is smoother than normal, here is the note from Cometic's website:

A surface finish of 50 RA (roughness average) or finer, is recommended for a proper gasket seal. Anything rougher may conflict with the gasket design.


My guy said that unless you specifically machine for this then it will not meet the spec, you may want to check with your machine shop.

The FelPro 1211S-3 has the extra bolt hole and the steel layer for strength. That's all my engine builder recommends

That's the key... Makes it a much better gasket than the 1211

He's a smart guy...

Kevlar is an aramid fiber.....just throwing that in.

i like the hardin ones the best, real heavy duty, seal very well around water ports. have used on a few 502's

i bought felprs, mr gasket, merc ones and hardins worked the best