1977 truck

[jason3456]

ok so here is the deal i have a 1977 chevy stepside with a 350 and it ran great for quite a while and one day i went to start it up and it back fired up in the carb like it flooded out so i tried again and it started up just fine but and it starts and runs great there is no sound of missing or valve problem but if you try to press the throttle it floods out and dies now the firing order is right the timings not off i put a new carb on it and its all adjusted in and cap and rotor are fine plugs wires are new and fuel lines are to right pressure im kinda getting at a loss because i have tried basicly everything everyone has said
 

[ericlb]

do a compression check on the ol girl you might have burnt valve
 

[noncompos]

Jason, you have to try harder to separate your statements (punctuation); when it all runs together it's hard to tell what's connected to what...that being said:
(1)"...it back fired up in the the carb like it flooded out...". That's a contradiction: coughing/backfiring up in the carb usually means too lean, not enough gas; "flooding out" is too much gas, usually prevents any firing at all, generates strong smell of liquid gasoline. If new carb still coughing/backfiring up thru carb, I'd look at things that restrict gas level/flow. like float setting, fuel pump, lines etc.
(2) stumbling, dying upon accelerating could be insufficient/no spark advance problems in dist; it could be carb dumping too much gas into engine, but it's hard to believe two carbs would each have the same flooding problem.
Restarting from flooding and dying usually requires many turns of starter before engine clears out gas, usually starts with black smoke and some "loping" from excess gas; restarrting from dying from too little gas usually requires pumping pedal (if carb has accel pump and depending upon electronics), no black smoke or loping.
Don't recall your original post, so don't know what-all you've looked at, or whether problems intermittent or not, whether same when engine cold and hot, etc. Good luck.
 

[rustyfarmall]

Sounds like it is time for a new timing gear and chain. Original gear has nylon covered teeth to make it run quiet. That nylon eventually gets brittle and breaks off, and then the camshaft jumps a tooth or two.