Need info on 2 ton spark plugs

[brewzer]

I am not familiar with 2 tons but a friend of mine just put a different head on his 2 ton and it does not take the standard spark lug. It has different threads. Did they make 2 different heads for the 2 ton? - Wally

[Jon]

Wally

some of the early tractors used a spark plug with a 1/2 inch pipe thread.

[brewzer]

Jon - thanks for the info. - Wally