I just looked in the Aeroquip catalogue. Unless i am overlooking something (quite easily) I am not finding a 1-1./2 SAE O-ring fitting.1-5/16, 1-9/16, 1-5/8, but no 1-1/2. Maybe double check the size in the valve cover. For the -12 AN hose, do you want 37 degree flare, 45 degree??? I don't think SAE 1-1/2 exists.
I put my caliper on the oil fill threaded cap and it is definitely 1-1/2".
My only other option is to drill out the top of the oil fill cap and tap a 1/2" NPT or a 3/4" npt hole and get a adapter fitting and thread it in the cap.
