.028 ok for my plug gap for my setup?

[1G90AWDTsi]

I have inverted dome top pistons .020 and port/polished the head...can I get away with the .028 spark plug gap or should I go a little lower like .023 or other recommendation??

 

[tkelly27]

It's generally recommended that you run the largest gap you can that keeps you from loosing top end and fouling plugs. When I'm not fixing my DSM I work on 80's turbo Dodge cars, they love more gap. I had a naturally aspirated version of the same engine that went from a snail at .035 to a tire smoker at .038. However they red line @ 6000rpm and the heads stop breathing efficiently well before then. Your mileage may vary.

Play around with it, you won't hurt anything, and plugs can be regapped indefinitely.