Engine: Copper coat Best Fiber head gasket?

[64studeavanti]

I just got a set of Best head gaskets. They appear to be some type of fiber over a metal core. I have always used Permatex copper coat on both the Felpro thin and thick head gaskets. Should I use this on these as well?

Any one have any experience on what these compress down to? They are currently .050 and I am hoping they compress to around .035 - .040

[StudeRich]

My guestimate based on the thickness of these "modern" material gaskets is, that a thick Gasket will reduce the advertised HP and compression to .5 less, usually 8.0 on most stock 259/289 Heads like casting 1557570, so these will reduce it to .25 less than stock 8.5, to 8.25.

On an Avanti with stock Flat Top Pistons that would be about 10.0 for an R1 or 9.25 on an R2 assuming no head or Block machining has been done or combustion chamber Porting.

I do not use "experimental type" gaskets so no idea of the best sealant.

[64studeavanti]

[53commander]

I got a set of Best head gaskets from Dave Thibeault and his recommendation was no sealer needed since they are made from modern material. I'm not sure of the compressed thickness but I'm sure Dave would know or could find out so give him a call he's a great guy to talk to.