These are modern, multi-layer steel gaskets. They are great for performance and race engines, and are in our opinion much better than the hard-to-find “Tii/turbo” cutting ring gaskets. (Why? with the cutting ring gasket, you may have to resurface every time you remove the head. With the multilayer gasket, this is not a problem, and you can even reuse them in a pinch.) The standard gasket is .051″ (1.3mm) compressed and will accept up to 90mm bore – the same specs as a standard factory gasket.
Option Note: We can also have these gaskets made to custom specs for larger bore diameters and/or different thicknesses by special order. This is a really nice option to resuscitate your otherwise-good race prepared head with a lot of labor in them which have been milled past minimum height and rendered unusable. Great for forced induction too. Select “custom size” and then enter the bore size and thickness in the text field (Note that custom sizes have a 2 week lead time).