for right now im using my oem HG....without the middle layer..its a stock block for now and i would like to keep it tha way...the cams im using require at least 11.0 CR and id like to get there with the stock b16 block...its a 1g b16 block with sir2 head...i got flat faced valves,the 2layer HG,and the head has been resurfaced..i dont know exactly how much they take off when they resurface but i believe its like .005.....so i figure i should be at around 10.7-10.8 right now....i just wanna know what layer of the HG are u guys using when running single layer? ive heard of people using the top layer as well as people using the middle...wondering if there is any risk in using a single layer HG? piston to valve contact crossed my mind but i dont think that should be a problem...what do you guys think?