it will change your compression and it adds just enough back with 2 layers to make it safe with pipes. 1 layer is more risky if you get some really bad gas and 2 would be safer as would the stock gasket.
tom one more thing larry (ncy)spoke of shims not sure which ones that he meant but he said i should replace them if the track is picked... spring shims or button shims
he means engagement shim...if picked use the shims...keeping the RPMS down I bet to prevent track spin on non-studded sled...you remember his exact words??