I'm new to the whole tuning process and the whole diagnostic deal.

My compression numbers: 170 168 175 157

Those seem a little low to me. Engine is an ls motor, stock bottom end, single layer headgasket and built head. There was an awful lot of oil on the 157 spark plug, I dont know if thats bad or what.

All of the spark plugs look like this:



When I first put the new head on, it smoked a pretty good amount. It wasnt distinctly white or distinctly black. I started running 93 octane and I have some Lucas oil goup in there now and it barely smokes at all. Can anyone tell if I am in bad shape or not?????

THANKS VERY MUCH