As mentioned, the stock pump is an electric in-tank pump, flowing 88 lph. Surprisingly durable, these pumps fuel the stock motor without much fuss. Now, change the motor a bit and a larger capacity pump is in order. What size, you ask? Let’s take a gander at the three most common sizes.
88-110 lph: There are both factory and aftermarket pumps out there that flow between 88 and 110 lph. Despite the latter being able to flow an additional 22 litres per hour over the stock pump, it is considered a stock replacement pump as well. If you intend to keep the motor stock, either of these sizes will do the trick. But then again, how many of use say to keep it stock and actually do…
190 lph: The next step up is a 190 litre per hour rated electric fuel pump. Definitely a huge upgrade from the stock pump, a 190 lph will do the trick for any naturally aspirated 302 engine out there.
255 lph: The last typical size to find in the Mustang aftermarket is a 255 lph pump. Just slightly more expensive than the 190 lph variety, the 255 is the most popular amongst Mustang enthusiasts.
Now, although the pumps are rated in litres per hour, it is important to know that you can install a 255 lph pump on a stock engine and not see any adverse effects. Foxboy Mustangs utilize a return fuel system, so there is no need to worry about the fuel pump sending too much, as whatever is not needed will simply be sent back to the tank via a return-line. Basically, going big can’t hurt. One last piece of advice: when a selecting a fuel pump, it is always better to go with a quality, known brand. There are some cheapies out there, but it definitely would not be fun to drop the tank a second time due to a premature failure.