Tell your guy to fit it will be ok to be honest about it i cant remember the last time i set a gap on a spark plug i have never had any problems with i mind years ago when i started out on forklifts when u used to get points in a distrubuter and i asked the same question about what to set the gap at and i got told to use the cardboard the points came in as the gap to adjust it to i laughed i thought the guy was being silly but i tried it and the truck started ok and the engine run fine and thats true.