Truck runs and idles rough

. My story: I have an 83 silverado once I got it it was great then it became a money pit, but after replacing just about everything, even getting a transmission repair, it isnt the end. One day after work, I was going uphill, the secondaries opened up as normal, but once I let off as I got off the exit it had no more acceleration and died, it was overheated, and needed oil, even after checking it that day and saying it was full, there were no leaks, until that night the engine died, after putting a quart of oil in it I could barely limp it home. So now I am afraid to drive it. It runs and idles rough. I have repleced distributor coil, cap, rotor, button before, this time I did everything but the coil, spark plugs and wires, fuel filter, new vacuum and coolant lines, valve cover gaskets, water pump, rebuilt the quadrajet, put JB Weld on the fuel wells that were a probable cause of leaking fuel causing it to run rich and making black exhaust, now it dont smoke, but when I changed the plugs, the drivers side was fouled but not passengers side, and the fuel mixture screw on one side has been twisted out more than the other, I changed the gas contaminated oil, and I have checked the timing and everything, pleas help!

P.S. There is a huge oil spill in the driveway, my truck never used to leak, until this dumb situation occured and am looking for help so I dont have to blow my checking account for a new engine that possibly wouldnt be necessary. Im sorry I have not done a compression or vacuum check to see if lifters have something to do with it. HELP ME!