47-55.1 1953 GMC fuel pump not working

[70gmc1500]

I have a 1953 GMC 9500 truck. This is a Canadian truck so it has a 235 Chevy engine in it. The old fuel pump was leaking so I replaced it. The new pump doesn't seem to work. There is fuel to the inlet of the pump but the pump doesn't seem to actually pump. I took the new pump back off and manually tested it and it works fine. I put it back on the truck and hooked up a small tank straight to the carb and ran the engine and the pump still isn't doing anything. I put my finger up to the outlet of the pump when the engine was running and there wasn't any pressure I could feel. My question is, is there somehow a way that I installed the pump wrong. The pump runs right off of the camshaft so I can't think of how it could be installed wrong? I felt the camshaft lobe too and I can't feel anything wrong on it either. The other thing is that the fuel pump has quite a bit of movement before it actually pumps, could it be that there is too much movement that the camshaft lobe doesn't push it far enough? Is there a way to possibly tighten up that movement so it pumps earlier in the stoke? Could it be something with the camshaft?

[mr48chev]

Did you compare the arm on the pump to the arm on the old pump? there is a change between 57 and older 235 engines and 58 and later 235 engines fuel pump wise.