DOES ANY ONE KNOW THE DIFFERENCE BETWEEN THESE TWO LS6 INTAKE MANIFOLD VALLEY COVERS, 12568002 AND 12577927? I AM GOING TO DO THE PCV COVERSION ON MY LS1 AND WANT TO KNOW WHICH ONE WOULD WORK BETTER OR HAS AN ADVANTAGE OVER THE OTHER. LOOKING ONLINE I FOUND THAT, IN GENERAL, THE 12577927 IS ABOUT $15.00 CHEAPER BUT I CAN’T OTHERWISE DISCERN ANY DIFFERENCE.