Sparkplugs for GN1-R heads for the street?


Active Member
Jun 3, 2001
Hey guys,

Finally got my car with stage II motor with GN1-R heads back but looking to see what plugs to run for the street. Since they only take 12mm plugs I am very limited. The car will be running e85 a friend said I may have a hard time running plugs for stree application.

The Autolite AR plugs wear fast because of the back cut ground strap. I run Autolite 103's on the street and AR3932 at the track. Are you sure you have the small plugs. I have a set of GN1r's on an engine in the corner, and they take the same as my regular GN1's.
Definitely smaller ones beacuase it was a headache to get the ones in have. Tom champion said ar4133 which are discontinued or ar 4172 which I only found on eBay. Awesome heads but smaller plugs kind of pain to find.
Oh crap sorry I was wrong AR4132-AR4133. That's what champion told me too. The 32's for higher boost