Got an Idea
 

Is it possible to change my 97 4.3 Vin W SCFI motor to Carb?
I would need to get a new manifold, a carb, possibly new heads? that is my only question would i need new heads? I would either get a tranny controller or swap for a 700. I would also change my ignition system to a MSD Complete system. Can this be Done? Im tired of Fuel Injection and the ecm holding me down, i wanna add a comp cam k kit headers, really max out the motor

also what should i do about fuel, pump etc

Anything is possible with time and money. Real question is why... Why is the FI holding you back? You can have your cake and eat it too. You just have to find a good PCM tuner to set up the PCM for your modifications.

What are you realistically expecting to get out of it?

If you are hell bent on going carb'd, you may want to first check with your local DMV as to whether you will be able to legally do so. If tha tis a-okay, then you will need to get a carb'd intake manifold for the vortec 4.3L engine, they do exist. Carb of your choice, ignition system of your choice, adjustable fuel pressure regulator to knock the pressure down to carb friendly pressures, bypassing the excess to the return line, expensive controller for the 4L60E, then you have to determine what no longer works inside your truck and rewire...

I wish you luck, but I think you will find that it is not worth the effort.