I started because the fuel gauge reading went kaput, and I traced it to the fuel sender. The replacement I received (VDO; fits all 240s) was too tall to fit in the tank. I would have to cut off a piece from the bottom of the return pipe. When I realized this, I decided to upgrade to the 740 style prepump and cut both the return pipe and the fuel inlet pipe. I used a Dremel tool for both. A pipe cutter or hacksaw wouldn't fit in the space for the inlet pipe without bending things. The total length that worked for me measure about 9 7/8 inches from the sender cap to the bottom of the pump/fuel return pipe. Happy for me, everything works after putting it all back together. I think the car is running better with the pump upgrade. But it wasn't a direct fit as I was told by sales rep. Oh and one of the leads came off, so I had to solder that back. I came away with a functioning fuel gauge, better running car, and new soldering iron and Dremel tool.