When I needed a pump for my 283 I got the least expensive mechanical pump that the national chain store had in stock, simple SBC pump, off brand. I just needed something to get the truck running so I could diagnose other issues. I have not checked the output pressure or volume but after pulling the engine and trans, new clutch, camshaft, lifters, chain and sprockets, seals and gaskets, new fuel tank, lines, carb kit, the truck has never failed to do it's job. 6 years on the no name pump. I know it's a different animal than the 6 cylinder pump, I don't know why it's still working!
