Ah ok, That's a big gap! I think mine are at .040 or .045. Just pulled some plugs again after hauling a couple heavy loads of lumber....load on truck and load on trailer....plugs are still looking new.
Did notice some carbon build up on one around the ridge....but nothing to be concerned about. I'll post some pictures of the load in my build thread. I was joking about a 750. haha The 600 is plenty for that motor, not enough RPM to justify the air....but those jugs sure draw some vacuum!