A lot of 6.0 Powerstroke owners who are doing head gaskets for a second time after a machine shop has already surfaced their heads find that the do not meet the minimum clearance spec. This head shim is .020 thick and will make up the difference for machined heads or blocks.
To install use Copper Coat high temp gasket compound to coat the block and one side of the shim. Then apply the shim to the block. You then install your regular head gasket onto the shim and reinstall the head following regular install procedures.
We have tested these shims on stock horsepower engines and engine with mild horsepower increases for over 100,000 miles with no problems.
(not recommended for extreme boost or horsepower applications)