RockAuto lists different ones for different wheelbase trucks. For instance, for my truck, Delco M10104 is listed for the 133 in wheelbase, M10101 is listed for the 119 in wheelbase. The only reason I can think of why wheelbase makes a difference is that the fuel tanks are different and the level sender might not be accurate in a tank it was not designed fro. Is there more to it like a different tank shape makes it not possible to mount a fuel pump not designed for that tank?
For the pumps that come without the sender, do you just transfer the existing sender on to the new pump?
For the pumps that come without the sender, do you just transfer the existing sender on to the new pump?