What are the most common plugs used with M&A heads both for the street (low boost & good driveability)and also for the drags (25+ psi boost) ? I purchased a "T" that has AC FR2LS plugs in it now. Are these a colder plug for racing ? If so, I want to use a warmer plug on the street. Which would be warmer, The FR1LS or FR3LS ? Any other suggestions ?
Thanks
Thanks