Oil Pan and Rear main parts advice

I used the Real Gasket oil pan gasket on my 1964 225, and also on my big-block recently. Seems wise. They began making silicone gaskets for aircraft piston engines, which is certainly more critical. No experience on the sealing since not driving them.

It is easy to change the rear oil seal with engine in the car. The slant has a separate aluminum seal holder as I recall, but even removing a main bearing block, like in a V-8 is not hard. The 2-piece crank seal pushes around. Insure the joint between the 2 pieces is offset from the block line, and I recall use a drop of superglue between the 2 parts. I think all rear seals I bought came with the side seals. I use Viton wherever I can. Unlike nitrile rubber, it lasts almost forever. I think it is the inner liner in both bio-diesel fuel hose and "barrier" AC hose. Similarly, I replace all vacuum and coolant hoses with silicone when I can. While you have the rear seal holder out, verify a gomer didn't strip the oil pan tapped holes. Now is the time to fix with a threaded insert (Heli-coil). Don't overtighten yourself, since easy to strip aluminum threads.