This kit lets Holley MPI, TBI, and Terminator EFI systems operate on vehicles with dual fuel tanks. Since these EFI systems require a fuel return line, the switching valve ensures fuel returns to the tank it was drawn from.
Specifications:
- For Holley MPI, TBI, and Terminator EFI Systems
- Rated for Systems up to 400 HP
- Includes Switching Valve, Relay, Switch, and Harness
- Part Number: 534-39
Installation also requires fuel hose, EFI pressure-rated hose clamps, 18-gauge wire, a 10-amp inline fuse, assorted terminals, and hose assembly lube (not included). The selection valve switches tanks by reversing polarity on the "D" and "E" terminals — many dual-tank trucks already have this type of valve and hardware.
FAQ
What EFI systems does this kit support?
Holley MPI, TBI, and Terminator EFI systems used on vehicles with dual fuel tanks.
What's included?
A switching valve, relay, switch, and wiring harness.
What else is needed for installation?
Fuel hose, EFI-rated hose clamps, 18-gauge wire, a 10-amp inline fuse, terminals, and assembly lube — none of which are included.
What's the maximum horsepower rating?
The kit is rated for fuel pump systems up to 400 HP.

