444 IH tractor, the aux. port on front of rockshaft housing, could it be british paralell thread, as i am haveing trouble finding correct fitting, sae is not working. thanks
Might be BSW (British Standard Whitworth) as the tractor appears to be made in England in the 70's.
Might be worth a google of a thread size chart. Might also try the national pipe thread, just by chance.