While on ebay I stumbled across head gaskets being sold for several engines (new and old) that I wasn't aware came with head gaskets from the factory in the first place. As an example, these include older/vintage engines such as the Veco .19 or the Enya 15-III and also many other newer engines which don't specify a head gasket. https://www.ebay.com/itm/Aftermarket...UAAOSwPbBc2ake I happen to have NIB examples of the Veco .19 and Enya .15 and neither of them have head gaskets from the factory.

What gives? These can't be performance enhancers since they would (albeit ever so slightly) lower the overall compression ratio . And with clean mating surfaces and proper torque spread among the head bolts leaks aren't usually a big concern. So are these to be looked at as "just in case" gaskets to prevent head leaks?

Signed: dazed and confused

Some people will lower the head by turning the head, or sleeve down, and then shim it back to there preferred head clearance.

Greg, that's true but wouldn't that be better done with metal shims and not paper gaskets. I just don't see how a compressible paper gasket that only comes in one thickness would be suitable for reliably adjusting compression or head clearance. Non-compressible metal shims in different thicknesses (.005, .010 etc) would be better for that task no?

Yes,today's technology would use metal shims. Engines built 40+ years ago had composition gaskets. Many of the engines I ran in the 60's 70's and early 80's had composition gaskets. K&B (Green Heads) McCoy (Red Heads) Fox's and a lot of other brands used composition gaskets. Production sport engines back then had broad tolerances, so thick compressible gaskets were common practice.