I am currently building an LS/Vtec and I plan on using CTR Pistons. I know that this will put me in the 12.5:1 CR. I only run a 91 or higher octane in my b16a right now and wouldn't plan on changing that habit. I am really worried about knocking/pinging. I've been told that If a I run a colder plug and a hotter ignition(MSD) that I should have no problems on pump gas. Can anyone comfirm this or have any experience with this setup? Any views are welcome. I just need to know before I go blow 3 bills on CTR's. BTW this forum rocks. Keep it up.