Just a heads up
Try a test fit when you get your adapters
When I received mine they were a bit to thick. The OD was fine.
I had to dress them down with a file.
Could of been a source for a leak
Good luck
This advice is important whether you use the adapters or you use the normal rings. This problem is not necessarily due to poor quality/thickness adapters (or rings). If the joint-surface on the manifolds (and/or head) has been ground/leveled/etc this might result in the ring being too "thick", and this would prevent the manifolds from being tightly attached-to head (resulting in leaks). In this case, as DADS50 stated, you have to dress/sand/grind off a enough material to allow a tight fit.
