I have 1970 AAR that I'm restoring back to original, when I purchased the car it had header's with stock oil adapter. I have removed the headers and want put on a original 90 degree oil adapter back on with manifolds.

My problem once I take the oil filter off i cant get the bolt off the engine which holds the oil filter to the engine, the nut which is 1 inch, but the head of the bolt is to small and difficult to get hold to take off, any ideas?