what is the gap suggested on IT20's with 4lbs? I thought it was .42", but after doing a few it just didnt see right. seems like it should be .38", but I just cant remember.

Chris

 

it looks like .38 is correct. there is a chart posted on page 6 from 4-14-05 under the topic "plug help" that will be good to print off. I believe it has the settings from any boost level on all the major plugs.......

 

With my ported eaton I'm at 0.032" Had them at 0.038-0.040 and did'nt realize I had a flutter around 4000 rpms. Gapped them down on advise of my tuner and I was a bit supprised at how much smoother it was. (4# lower on my truck)

Rich