[71 Puller]

What are you guys running for spark plugs in your cj heads. msd 6al ign,11.5-1 comp 93 oct fuel.

 

[hookin78]

We seem to have good luck with Autolite #25's

13.7 to 1

8000 rpm is normal on the track

Iron CJ's

 

[Mark Laczo]

plugs

Right now AR 24's may go to the 25's next. 23 are stock heat range I think.

 

[71 Puller]

What are you gapping them at.

 

[Lem Evans]

If a guy has big comp. ratio and high rpm.....AR-13 and AR-12 may work good.