Well Mako, good sensible advice but I went a little different route for my baby...
This is what I came up with after talking with Hector at Ricks Hot Rod Shop, aka. Ricks' Tanks.
Taking the leap from this crusty 44 year old pickup and sending unit:

To this low pressure "in tank" pump with an aftermarket sending unit:

With this package should I ever want to change to an LS or EFI it is only a pump change... and regulator etc... but you get the idea. The goal or theme here is that the parts going into the car will lend support to mods in the future. You know,
"Someday".
Here is a side by side comparison showing the clipped corners for exhaust packaging or possible future mini-tub or link style rear suspension clearance.