John Deere G with power block

[JerryCoolRep]

Hello, I'm rebuilding a G that had a power block kit on it. I am having trouble finding spark plugs for it. Deere says it should have a b&s part # 491055t or Deere part # m78543. It is too small thread size. somewhere else I got a Autolite 3076 which has 7/8 nf thread and it is too big. Need something about half way between. I'm more of a diesel guy and not very good with spark plugs. anyone have any Idea? Thanks a lot!!

 

[a49deere]

goggle says NGK AB-6 for what it's worth!

 

[JerryCoolRep]

I fond a Autolite 386 fits. The parts guy at car quest looked it up and found it.