Fuel pump won't stop running but truck won't start until gas sprayed into intake, then runs lean.

Replaced engine,replaced #5 injector, fuel pressure regulator,fuel pump relay, coil, ignition modulator & distributor. At first ran well then rough that seem to clear up upon turning overdrive off. Now the light on the overdrive button is no longer lit & it will not deactivate. Truck will not pull in drive, only in 1 or 2, reverse is fine. Black smoke rolls out the exhaust & the fumes will choke you to death.It has dual gas tanks with 1 pump. I am at a total loss.