Autolite 458 spark plugs

[Tom N MS]

Any thoughts--good, bad or otherwise? I Put em in my 2N today..

 

[Randyr]

437 is the recomended plug on the Autolite site.
The 458 has the same thread so it will screw in, but the reach is bit short at 3/8" vs 7/16" for the 437, and the heat range is wrong at A7 vs C8 for the 437.

 

[Dell (WA)]

Tom..........WRONG PLUG!!!........the SHORT thread (3/8") will allow yer cylinder head threads to "carbon-up" and you will NEVER be able to use the correct recommended longer thread (7/16") hotter 437's. ........Dell, yer self-appointed sparkie-meister

 

[Den N Ms]

Tom,If its fouling plugs out they will stay firing longer than a 437 plug will.They are one heat range hotter than the 437s.

 

[NoNewParts]

like Den said

I ran 458's in a couple of oil fouling cylinders on a N
until I had a chance to tear it down and fix it.
worked fine