Also, if I get a new head gasket, should I get a thinner one to increase compression a little? I only have external mods and a roe racing stage 3 tune for 92 octane, AMR long tubes, high flow cats, throttle body, ram air intake, hipo ignition and wires. ROE Racing is out of biz and I cant afford a new tune. Can I install the heads without removing the rocker and everything?