Hey Otto,
I average a little over 14 MPG. I have about 1000 miles on the truck since the modification. I’m mulling over taller tires as an attempt to improve mileage a bit.
I don’t want to jinx myself but so far it’s worked flawlessly. I did have an annoying whine from the fuel pump but I tracked that down to the steel fuel pressure line from the tank to engine compartment. Better clamping of the line resolved that issue. I did have to play with the fuel enrichment adjustment for starting to get it to start better cold. The adjustment for fuel enrichment is done via the controller as are most adjustments and is very easy to do.
If you’re OK with keeping the tank in the cab and you don’t mind the noise an external pump makes, then yes the in cab tank can be used. My Task Force truck’s fuel tank had a drain plug (not sure if an AD tank is the same) that could be used for the return and yes you do need a return. The throttle body incorporates a regulator that regulates fuel pressure to 58 psi and Holley recommends a pump that supplies 60 psi.
Speedway has the Quick Start Manual and the Installation Manual posted on their website for the Sniper unit. Two great resources.
I paid a little less then $800 for the Sniper unit. I have about the same amount in a fuel tank, Holley in tank pump/sending unit, steel pressure and return lines, fittings, fuel tank straps, fuel pump block off plate and a fuel indicating unit to marry the mismatched tank sending unit and the fuel gauge. My brother in law fabricated the throttle body to manifold adapter at no charge for putting up with his sister. Utilizing your in cab tank will reduce the cost of installation a bit but keep in mind you’ll still need an external fuel pump and they’re expensive.
