Well my oil cooler lines have been removed & an adapter a shorter oil filter installed. The oil pressure has definitely went up.
Does anyone know what size the threads in the radiator are? They are much bigger than 3/8 pipe plugs. I think they are AN fittings.
I tried a 3/4 fine thread bolt but it was loose. I do not have a larger bolt at this time. I do not want to cut the old lines and plug the ends in case I need to go back to them.
An AN10 fitting is 7/8-14. Is that the size of the threads.

 

Did you get the size figured out? Other than taking the line to the store to compare, you can measure the length and diameter of the fitting and count the threads to determine the size/pitch.

 

I just used some rubber plugs.