Does anyone know the difference between a 1941 plymouth flathead dual action fuel pump and a 36-38 plymouth dual action fuel pump. I found a 36-38 nos and thought they would be the same, but the box says 36 to 38 plymouth. Arn't the blocks and cams the same? Is the difference in the gas fittings. Thanks in advance.
mike
The 1936-48 Plymouth parts book shows part number 659488 for 1936-38 cars and trucks as well as the 39, 40 and 40 trucks. It shows part number 583056 for the 1939-48 cars. Not sure what the difference is, the 1939-48 entries for the parts inside the pump are filled with detailed notes that would take some time to go through.
For what it is worth the pump to block gasket (part 688482) is the same for all 1936-48 Plymouths.
I'm not sure about the differences, however, be aware that your nos fuel pump probably needs to be rebuilt before you can use it. Those old parts won't hold up to today's gasolines.
Were that NOS pump made in 1938, they would have no way of knowing whether the 1941 Plymouth would still be using said pump with out benefit of Dr. Emmett Brown and a DeLorean. The only reason for variations in fuel pumps for MoPar L6, that I am aware, is clearance between exhaust manifolds and fenders. I second the motion to have rebuilt before installing. While not a technically difficult job swapping fuel pumps out, it is still a hassle. I just swapped out a fuel pump on my '46 P15S more door this week end, and am amased at what a difference it made in performance. Old pump has been limping along for years judging by how much better new unit performs.
Thanks, I do plan on rebuilding the pump with a modern kit. The difference must be in the manifold clearance as you said. I guess the only way to know is buy it and put tem side-by side. Thanks for the replies, Mike