*edit* The low pressure VL (VN/VP long range tank etc etc) internal pump is different to the standard in tank VN-VS pump, it's shorter and looking at the 2 sender units it sits slightly higher off the bottom of the tank than the later model ones, you
can't put a VN-VS pump into a vl sender for a single pump setup.
VN top, VL bottom, apart from fuel pump size the electrical connections differ.
Now you can use a VN sender unit with the single pump and convert the system easily, the external plugs are the same (also shared with VP but some VP's have the return line in the sender as per below)
Some VP/VR/VS sender units will work but they need to be the short ones as there is a longer variant that has the distance from the pump and the plate longer as they will not sit the pump in the swirl pot, keep in mind they also have the return line as part of this that will need to be blocked and if going VR/VS have different external plugs.
I've used an external VL fuel pump on a few occasions to drain tanks with them sitting on the ground and the hose going up to the filler and back down to the tank, they have enough suction power, i'm still unsure why they had to use 2 pumps, using an external pump is so much better when it comes to fixing a dead one, personally i'd go for a good quality rebuildable external pump and just put a sock filter and a piece of metal fuel line in place of the internal pump anyday...... quick ebay search, for $200-$300 you can get something like this (if you like quality, otherwise i'm sure there are cheaper options or if like myself you tend to drive these earlier models due to being cheap runabouts and can keep the good bits and pass it onto the next cheap shitter for reliability) and when it shits itself you can shove a $50 rebuild kit through it repeatedly, if you're cheap then this isn't the option for you but if you hate having to drain tanks and stink of petrol each time you need to replace one on a car you plan to own for a long time......
