So in every gear and usually at high rpms the engine will stutter or miss like it's cutting out. Messed with all the timing except the timing chain. Does a worn chain or tenchiners let the engine do that? It's the L16 1973 620, with about 100,000 original miles on it. It does have a Weber carborator on it with some vacuum lines not being used anymore, they have bolts in the ends of them, and that's how I bought it, haven't messed with them at all. The truck sat for awhile and when I first started driving it,it was fine, and now that I'm driving it alot more it's starting to act up on me.