Includes standard thickness 12 valve Cummins gasket modified for the use of fire rings.

Requires the machining of grooves into the cylinder head or engine block for use.

6 mild steel rings included.

If you plan on using 12mm head studs, groove depth needs to be: 31-32 thousandths deep, with a width of 120 thousandths.

If you plan on using 14mm head studs, groove depth needs to be: 29-30 thousandths deep, with a width of 120 thousandths.