So I just got my 13.5:1 comp 370 running on a mail order tune and after breaking it in for a couple days I took it out and opened it up. Car pulls very hard when your rolling into it but after you get past 3/4 throttle it seems to stop pulling. The fuel pressure didnt drop at all and I do not have a wideband so I shut the car off on the next pull at WOT and pulled some spark plugs, they were white. Now I am running straight 112 octaine, Is the fuel turning the plug white or could it be running way to lean?

 

White is very lean. You might want to get a dyno tune, mail orders aren't the most accurate. Also what plugs are you running?

 

Im running the tr6 plug at .035" gap

 

I've heard that race fuel will give a white'ish color on the plugs.