Steel shim head gaskets used in lieu of using composition gaskets will allow for an increase in compression ratio at the risk of some water seepage to the outside of the engine if head and deck surfaces are not perfectly true.  The FelPro composition gaskets on the other hand do not require retorquing after the engine has been cranked up while also minimizing any coolant leakage problems.

Another advantage to using the composition head gaskets is that it allows the heads and/or decks to be milled 0.015” while putting the intake bolts back in the original positions.  Milling decks or heads while using steel shim gaskets puts the intake bolts at a lower than stock position from the git go and any excessive milling can force the intake manifold or the intake side of the head to be milled in which to restore the fit.

Steel shim head gaskets are about 0.025” thick while composition gaskets are in the 0.041” neighborhood which accounts for about a 4.3cc difference between them.  This in turn makes for about a 0.4:1 change in compression ratio on a run of the mill 292.

Duck, when I pulled the 553 off my engine, and subsequently the heads, I too had steel intake gaskets as well as head gaskets. Just thought I'd add my name to the (apparently) short list who've had steel gaskets.

By the responses above, I think I'll be going with composition gaskets as well...I will say though, the steel gaskets sure are nice how they come of if one piece

Ted always says it best.