I would not run a 2 layer HG. You just don't get the same seal and reliability. If you want a little extra bump in compression run a flat face valve or do a .020/.030 mill on the head, never hurts to make sure that you have a nice flat surface to mate to your block. You can get good gains without upping compression with S2S2 cams as long as supporting mods are in place: GOOD HEADER!, intake manifold that will help make that power up high, something to tune with, either obd1 running crome/uber, hondata etc. Good luck