bjuice

Ed is correct and so was the lasts 2 guys..however you need to know that to get an accurate plug reading you must kill the car right after the pass and pull the plugs before you come back to pits..or get a tow back with car shut off..if the car is too lean at WOT...after you creep back to the pits the plugs will change causes inaccurate plug reading..

just a little tid-bit on that one..

i tell ya whats the best ivestment you can do..is the clamp on style EGT sensors..drill a 1/4 hole or smaller ( whatever the probe is) insert the probe into your header primary and use the cirlce clamp to hold it in place..( no welding required)...you can check exhaust temp gases from inside the cock pit and know where you stand at all times...most guys running alcohol use them ( BLOWN ALCHOL) paticulary..you can find these entire sets ups on e-bay pretty reasonable..

thnaks brian