Can anyone tell me how to get colder plugs? What are model numbers for colder heat range plugs (2 heat ranges) for an L98 Engine? What do I ask an auto parts guy when looking for a colder plug? Thanks in advance. I am running a 100 shot and need two heat range colder.

 

Most spark plug part #s run low to high in terms of heat range (i.e. a champion RV9YC plug is 3 steps colder than RV12YC). ask the parts counter guy if in doubt it is an easy request. Unless you are spraying more than 100hp leave the plugs alone and just put in some good gas. Cold plugs will foul easier when not on the spray.

 

Don't use platinum and don't forget to retard the timing.
I'm running the autolite 3924's. They're 2 steps colder. And yes, they foul often b/c its my daily driver, but they're on $1.19 a plug!