Quinn, I reread your title your original plans and original goals,now teamed up with,you want a new carbureator. This is about a simple and budget friendly as you are going to get, go to pick n pull ,preferably on 1/2 price day. Pull a complete l31 vortec engine,transmission ECM and as much wiring as you can snag. Now you've got a Vortec engine,steeper 1st gear, and over drive. The Vortec engine bolts in,bolt for bolt. The modern engine management is going to be a night and day difference on drivabilty and mpg. If you add a small cam and headers to equation,you are going to think you have the fastest truck in your state. Measure your driveshaft get 1 an inch shorter hopefully out of the donor,relocate your transmission crossmember,and buy an appropriate fuel pump. You can wiki l31 vehicles there's tons of them