Fuel tank conversion

Want to convert from a trouble-plagued dual tank system to a single rear-mounted fuel tank with a mechanical fuel pump and an inline electric fuel pump to aid in getting fuel directly to the mechanical pump and onto the holley carburetor. Want to eliminate 6 port valve switch and as many relays, switches, regulators, and as much of the wiring that I think was designed for an EFI unit. The previous owner put a fresh motor in and had so much trouble with the dual tank system system he parked it for 10 years and finally sold it to me. Everything so corroded I had to get a bucket of fuel and run a hose into carburetor just to make sure it ran. The engine has 28,000 on it with a new Holley 4180 [4160?] Sitting on top. Sounds sweet but I don't know the previous set-up. Dropped both tanks and it appears the front tank was never used. Cleaned and reinstalled rear 19 gal. Tank with elect. Pump inside. Don't need or want 2 tanks. Any help or advice on conversion would be greatly appreciated.