Hello, I have a 49 studebaker pickup on a 93 Ford Ranger frame with a pontiac 350 vortex and a 700R4 trans. Its going to be a awesome ride. It also has the steering column from the firebird donor.
Okay the problem; I still have the wiring harness from the Ranger. It has the independent bulb system and I want to go a common system with one bulb for turn, brakes, and taillights. I bought a trailer converter but can't make it work. I would even be open to striping out the wiring and installing a new common system but I don't know how. I know that I am not the only one to want to do this, just the latest. Can anyone help? Thanks very much.  

I believe this should be fairly easy.  Pick up a set of common sockets(which you probably already have) and there should be either three wires or two if the socket is grounded through the socket itself.  1 wire will be for turn, one for brake and if there is a third one for the ground.  I believe there is only one bulb for the brake and one signal per side from what I see on the pics of them.  Hopefully this helps.  

You are going to need to get the wiring diagram for the Pontiac Firebird turn signal switch and match your wires to it. That will allow you to get back down to just two bulbs in the rear, UNLESS the Pontiac also had seperate bulbs for each function, and of my own knowledge I do not know.