I'm at my witts end. I know my idle speed is low, but I have re set my timing. It is set at about 11. It revs fine and sounds great in the garage. But as soon as I go to drive it, It lacks power and backfires, and backfires more the harder I push on the gas pedal. Anyone have any ideas.

Please help me

 

Backfire:
1. Bad fuel or emissions systems
2. Timing (11 is fine if you did with the ECT dx'd)
3. Ignition problems, cap/rotor, wres, plugs, etc
5. Vac Leak
6. Valves hanging open

(not listed in my book, but I belive if the cat is plugged, it will backfire also?)

Engine Lacks Power:
could be anything not set, adjusted right, or worn. Could be more then 100 things.

 

Timing maybe redoing it tomorrow. Cap, rotor, wires, and plugs replaced, no vacume leaks i can tell. Fuel good refilled tank with premium. redid rockers and all new tappets( those sound better than a new cars). Any other ideas