I have a 1994 GMC 1500 4x4 Sierra. I want to know if i can put a carb on it and an earlier style ignition. If so What all do i have to change out.
You can't with a EFI system engine, unless your planing to use the Sierra as off road use only. You can not convert EFI engine to Carb engine and run them on the road.
Why do you want to go from fuel injection to carb? If your Sierra is a daily driver that is fairly stock then you are just wasting your time and money. Your gas mileage will decrease, you will lose some low end torque, you will lose some drive-ability, you will increase your exhaust emissions, and decrease the value of your car.
Don't get me wrong, a good well thought out carburated combo is a very good system. But if you are switching to a carb just to solve your problems with EFI you might be surprised. A carburetor requires work to get it right.
You may be trading in your problems for a whole new set of problems that you know nothing about. Before doing anything carefully weigh out your decision to remove the factory system from your Sierra. In the end I hope that whatever decision you make turns out to be the best for you and your Sierra. GOOD LUCK!!!
Mechanical Changes
Intake and Carburetor: Of course if you are converting from EFI to carb you must have an intake manifold and a carburetor. Just be sure to size the components to match your combination properly.
Fuel System: You will need a new fuel pump and pickup. Do NOT use the existing EFI pump. You can either use an electric low pressure pump designed for a carb (like the Holley red or blue pumps) or go with a mechanical fuel pump. In either case you must replace the fuel pickup on top of the gas tank with a purpose built pickup that does not include an in-tank pump.
Ignition: This distributor has a steel gear to be compatible with a roller cam. Also use a complete MSD distributor and box could also be used as a step up from the factory stuff.
Transmission: This is probably the most critical step of the whole process. If you have a manual transmission you have nothing to worry about. However Carburated engines can be joined to the 4L60-E by use of a GM Controller, #12497316. Carbureted engines will require a Throttle Postion Sensor. Setup is critical so follow the instructions included closely. Setting up the cable wrong will lead to a burned up transmission in very short order.
As for electrical there are lots of cutting and eliminating extra wire that is not needed to eliminate to keep any unwanted shorts.
