Okay guys I need a lot of help with this one. My truck was running bad so me and my brother messed with the timing. Took it for a spin. Ran great. Been driving it all day today and ran great, until like 10 minutes ago. It started sputtering really bad like I could barely press on the gas. So I babied it trying to make it home and down the street on court and walnut it backfired. First time it's ever done that. What would cause it? I have no clue what's wrong with it. It sounded like the timing was off, but I checked the distributor just now and it was on there tight enough I couldn't move it. So idk what it could be