canister oil filter to spin on conversion nut removal

[ahshoe]

I have the spin on kit already for my 56 F100 272 ci. I am trying to remove the old large female nut that holds the plate on for the canister filter. That bugger will not budge. I have to remove it to use the spin on large nut with the male threads on it. I tried a breaker bar. According to the new threads I can see that it is a left (counter clockwise) rotation to remove the old nut. Any thoughts?