Spark plug no longer aval . ac 43N
Thats the plug heads orignally took . I heard to use delco r43xls now . Do i need to go up or down in heat range since i'am 30 over now and added a bigger cam and about .5 point compression , gears and a convertor . I don't drive the car on the street , its just a toy at the track . I tried NGK bpr4es but the plugs stay very white and i get a pop now and then at idle ,more so when engine is not to operating temp . ( I think that means the plug is too hot correct ? ) i have msd ing and 6al box if that matters . I gapped the plugs at .35 also .