fuel system wiring to bypass computer after TBI to carb

[mshawn]

An 87 truck will be a mechanical speedometer.

There's quite a few ways to go about this. The simplest way would be to just keep everything as original as possible. Only disconnect the plugs on the intake that you have to(distributor, TBI) and swap the intake to a Carb one. Swap the distributor and coil to an HEI unit. Then just run the fuel pressure regulator to the carb. You can connect the tach signal and ignition hot wire from the old system to the HEI and that's all you should need. Leave everything else in place and put the TBI intake and throttle body in a box just in case you sell it. Personally I would keep the TBI, and if you ever want to sell it you cut a huge amount of the value out of the truck if you hack up the original stuff when you convert. If you leave everything reversible, you get the best of both worlds and could sell it to someone that prefers carb OR to someone that wants the EFI

I totally agree with this, this switch is pretty straight forward on an 1987 c/k truck . Need help let me know. Take it 1 system at a time. 1987 tbi for v8 truck fuel pump pressure is 9-14 psi if I remember right so your in the range for a carb, just have to regulate it down a few psi . Distributor is the same positive wire and ground wire going to the tbi distributor. Just make the connectors fit hei distributor. As far as the fuel pump relay and low pressure switch, they will work the same don’t touch them. The ecm( computer) has nothing to do with them. The switch when It gets low oil pressure it interrupts power to fuel pump, that wiring is ok. So from there you should be set. Find a port to set your vacuum advance on your carb. Which should be ported vacuum, and your good. Let me know if I can help further.