[fred cook]

I am about to start a rebuild on a 3.0 block using 100mm pistons and cylinders. The pistons are Mahle cast to give 10.1:1 compression ratio. Cams will be from a 964 and I have an Electromotive XDi ignition to provide spark. I will be using ported Carrera heads that have been twin plugged. I need some input as to what brand and heat range spark plugs to use. The heads are cut for 12mm plugs. It's probably appropriate that it is nearly Halloween since I am "lost as a haint" as to which plugs to use! Total advance will most likely be in the 22-24 degree range.