Hmmm... two very different opinions on plugs.

Eckerich - 10.5 -11.5
Ludwig - 7, maybe 9

I'm picking up the Magnecor 8.5mm wires but am lost as too what plugs now. The "other" NGK plugs I had tried were some that were supposed to sit deeper in and required a special spark plug socket that had been machined down just to get them tightened. On the dyno, they did nothing and I did back to back testing. I would prefer not to buy and test more plugs. If 7's and 9's like stock is not ideal, then ???? Some part numbers would help, I have the ones for 7's and 9's but not others.