I can appreciate that information. Cool stuff. I never thought gas, hi compression and no spark plug was even an idea? I hate what they did in the 70's. I always found myself in an emissions mandatory area. You seam real knowledgeable, What does LS stand for? I am currently exploring my wifes 07 Impala SS 5.3L Excessive tapping, Miss fire cylinder 4. Her engine and my 6.0L both have tapped in the winter. My 6.0 even has piston slap like it has forged pistons. I have had the new lifters installed on mine but it still tapped. I have the 5.3L torn down to the cylinder heads, There next and so far all normal wear. My plan is to replace the Lifters, thinking they are damaged. I am not sure but I guess I will find out? What is all the solenoids and electrical I found on the valley cover? I know it is the cylinder deactivation system But how in gods name does it work and why is it in the crank case? Hey if you don't know it's cool just questions yet to be answered.