Small block head gasket research project

[Clem Z.]

Re: Small block head gasket research project

the stamped steel gaskets can be identified by the shape of the hole or lack of it on the exposed end of the gasket. the 711 gasket has a round hole and the 631 does not have any hole. this was true years ago when i was doing tech inspections for drag racing and engine building.if you use double gaskets you only need to add .003/.004 to the total compressed thickness,not .006/.008

[John M.]

Re: Small block head gasket research project

Duke,
I have both of these gaskets here on my desk today. The original measures 0.018" +/- .001" everywhere including the non-compressed and compressed areas. It has no hole in the corner and I'm 99% sure its the original. I also have a new GM set of 0711s in the GM package (hole in corner). They measure 0.021"- .0215" on the shim. Measurements made with micrometer out of a qualified QA system. I think I measured these earlier at home at 0.026" which must have included the rubbery sealer on them.
John McRae