I found 386's to be hot plugs, and would eventually erode.
L14U's are equivalent to the Autolite 386's. Pretty much the same story.
Autolite 373's would be worth a try, even though they are non-resistor plugs.
Denso M22's would also be worth a try. Price is right:
Worth noting I've been NOT USING any sort of antiseize on spark plugs on the airplanes I maintain for several years now. They spin out easily and cleanly. Antiseize, even the **** Champion stuff, gums up threads.
Bob Japundza CFI A&PIA
N55BC RV-6 borrowed, flying
N678X F1 Rocket, under const.
N244BJ RV-6 "victim of SNF tornado" 1200+ hrs, rebuilding
N8155F C150 flying
N7925P PA-24-250 Comanche, restoring
Not a thing I own is stock.
Last edited by rocketbob : 02-02-2019 at 10:41 AM.