Dumb master cylinder question.

Look into a Dodge Diplomat M body aluminum master cylinder. Bore is 1&1/32" bore. Piston has a groove for a manual brake pushrod O ring, and uses SAE fittings. Rock auto has em. Get a 2 bolt to 4 bolt adaptor plate from doctor diff. About $38 comes w replacement pushrod o ring. I will be using a GM combination valve and plumbing it all myself. If your going 4 wheel disc, you can buy a GM 4 wheel disc combination valve, and might need a residual pressure valve for the rear brakes.