It's looking like NGK 8's on the top and matching 8s on the bottom. I figure colder is better than hotter. The motor will run plenty hot anyway so the worst that can happen is I have to warm up longer to get the plugs firing well. However if I go one hotter anywhere I risk creating a pre-ignition inducing hot spot in an already detonation prone motor. That could mean engine damage.
Also thinking of going with the irridiums. I always liked my Bosch Platinums. Better flow around the plug nose. Haven't found indexing washers yet.