I have a 12.2-1 464, 260-280 @ .050 solid cam, Iron heads that flow 258 CFM, 1090 Dominator, MSD ignition in a GS. Which brand spark plugs should I run and which gap? I am leaning towards NGK. Suggestions? I will be putting aluminum Stage 2 heads on the same engine when TA has the next batch ready to ship. Which plugs for this combo? Thanks! Tom Jenkins
PLUGS IN A COMBINATION ALMOST EXACTLY LIKE YOURS, I HAVE RUN AUTOLITE #23'S GAPPED AT .035" WITH GOOD RESULTS.
Depends on the compression ratio Marco. For our cars with under 10.5:1, .050-.060, 10.5 - 13:1, .040-.050, and above 13:1, .035-.045. Those are MSD's recommendations. NGK's are quality plugs. Right now I'm running the UR-55's gapped at .050, so far so good. UR-4's are the stock replacement, UR-5's are one step colder. I might try a UR-6 next.
I run the UR5 NGK plugs in mine with a gap of .030. I have tried lots of plugs and this works best for me. Our engine combos are very similar so should be good for yours also.
So you're saying to use the same plugs for both iron Stage 1 heads and aluminum Stage 2 heads? I talked to Mike at TA today and he said it may take up to 3 months before the next batch of Stage 2 heads are ready. I was hoping to see them in time for Salem, or even the Midwest Buick Challenge. Oh well! Thanks for the replies! Tom Jenkins
No they take different plugs. The iron heads use plugs with taper seats and short threads. The aluminum heads use a long thread with washer seats. There was another thread on here a while back with recomendations for those plugs.
