he put his GOOD gas tank and pump from the old truck into this one.

Luke, seriously, in the best interest of getting the thing running, have your friend come back over and clean the carb.

he seems like a nice helpful guy, but no one likes to work for free, so be ready to give him something, 40-100 bucks at least for the hour or two hell spend on it. its still WAY cheaper than actually taking it to a shop and he will show you the proper way to clean it, how it works, and if something ever happens in the future you know how to take care of it. its very rare for people to know someone who is that knowledgeable and willing to help, so take advantage of it, but not of him.

you can try to clean the carb yourself but they are tricky and easy to really screw something up.

my guess is that the float is stuck open from old gas and flooding the engine, the fire was from the carb throat where air goes in, thats the only place where it could have combusted, not inside the carb.