1984 Dodge Ram Bad tuneup?

I have a 1984 Dodge Ram B250 custom van. 225 slant six. It was driving well enough, though it started hard and was losing power up hills. I put on a fuel filter. A friend put on a fuel pump. But here is when everything went haywire. He did a partial tuneup. Checked each plug and wire. Wires had spark but he said three plugs were dead. He replaced those three plus cap and rotor. The one plug had a helacoil and instead of replacing it, he pulled it off and put it on the new plug. Then, he had the wrong firing order. But still he was revving it up for 5 minutes even though it was popping and smoke coming from the carbeurator. He fixed the firing order the next day. NOW the van is undriveable. It won`t stay running and it bogs down at varying speeds. Bogs down so bad that it has been parked ever since(one month). He insists that its the carb but I don`t buy it. Is it coincidence then that the carb mysteriously dies immediately after the "tuneup?" How much damage could have been caused? Could my electrical system be fried? Am I now looking at hundreds of dollars in repairs or replacing the van? Thanks. Hope you can give me some insight.'.