Mr Stang, a stock Ford electric fuel pump substitutes for about the last 4" or so of a late Pantera fuel sender line. The pump has a built-in replaceable filter on its bottom intake. It should rest on the tank bottom. You'll need to route 12V to the pump inside the tank and ground the other lead. No special precautions need be done since the oxygen-poor mixture inside a gas tank is non-combustible, so electrical spade lugs work fine- just like stock. Note there are two identical appearing pumps available from Ford: one puts out about 12 psi for TBI fuel injection and can be regulated down to 6-7 psi for a carb. The second type puts out 45-60 psi and is for true EFI. It CANNOT be regulated down to carb pressures. Both Ford pumps fit thru the stock sender hole in an unmodified Pantera fuel tank. Aftermarket pumps may be too large to fit thru the provided tank hole.
* A few more notes: Bondo, once cured, is totally fuel-proof so it makes sealing off the new power wire simple. The stock '71-'72 Pantera gas tank has an integral fuel-out line that can be used as a convenient return line for EFI, with the later '73-up sender supplying the new fuel-out line.
* Depending on what you have in mind, stock fuel lines are too small to support much above 450 bhp continuous, but with some work, a piece of 3/8" line can be substituted for the less-than-5/16" ID line in the late sender. The banjo fitting on top of early tank outlets is even more of a flow restriction.
* Be extremely careful in choosing your in-tank connecting hoses. I have several feet of brand new rubber gas line labeled 'Fuel-Proof' that swells and delaminates in less than a month when soaked in what is sold as 'gasoline' these days. Test what you buy- parts counter people lie.
* Drill out the rivets on the stock fuel tank vent and substitute a Hall Pantera anti-rollover vent-valve. It adapts a late Ford anti-rollover vent-valve. Last I looked the cost was less than $40. Anyone that runs a modified performance car these days and does NOT use one, is flirting with total disaster.
* So what's the advantage of an in-tank pump? First, it is quiet- something NO aftermarket external pump can claim. The constant drone of an external pump during a long road trip will really begin to bug you after a day or so. Second, it is unlikely to ever be damaged by road debris or from an accident while inside. Third, if you use a STOCK FORD EFI pump, you have the benefit of millions of other cars having tested the pump for decades. With an aftermarket pump, YOU are the entire Testing/QC department. Good luck.