Slight miss when cruising

Increasing the size of the fuel lines? I don't think that could be the problem at all......if it were, you'd definitely know it at WOT. You're using a very small volume of fuel while at cruise. I think you may be experiencing pre-ignition, not a miss. I've replaced my spark plugs and gotten rid of this problem before. Couldn't figure out why, because the plugs I took out looked perfect.

I'd also back off the timing a few degrees right off the bat, just to see what happens too.