I have a basic idea when it comes to working on fuel injected cars, but I just bought this D150 from 1979 and it has a carb. Beautiful truck but as simple as they were back then i have no idea what I'm doing. For instance, It backfires through the carb. Not violently, but often. Every other second or so when it decides to run. Any ideas?

 

If it backfires through the tail pipe then it's the carb, if it backfires through the carb it's the timing. Check the distributor cap, rotor, and overall timing. It could be other things, but these are usually the culprits.