454 Chevy engine backfires

Some years ago I bought a beautiful 88 allegro with 454 loaded with smog stuff. the first thing I did was replace the timing chain and gears with a full roller with straight up keyways add dual exhaust and get rid of all smog stuff.That thing ran like a scalded dog. Because we know smog motors have keyways cut 4-8 degrees retarded.....so, did you use your old retarded chain and gears? If not ,did you degree your cam to see if it was retarded? just a thought.....like a doctor you have to eliminate everything.

wheelmanii wrote:
My 1996 Chevy 454 was doing the same thing. I replaced the plug wires with an after market set. Solved my problem.

X2
Had the same problem. The stock exhaust manifolds make it very easy to burn the spark plug wire insulation causing an intermitant spark and backfiring.

My 1996 Chevy 454 was doing the same thing. I replaced the plug wires with an after market set. Solved my problem.

Try some Red Line Fuel System Cleaner.

His dizzy is fully motorized, so no springs. I'm thinking running lean, especially since its only under hard acceleration. Was the tank left full when parked? Are you still running on old gas?

Alright, now we know what we are working with. What was the question again? Oh, yea, backfiring under hard acceleration.
Can be one of the following.
1. timing
2. vacuum line
3. distributor springs
4. loose throttle body
5. plugs or plug wires

1996 fletwood southwind 454 ci rochester TBI, single coil, changed the fuel filter.

Change the fuel filter.

As previous posters state need more info. However, one place to start is wait until it is dark outside, close shades, open doghouse and start engine. Look for sparks around plug wires, distributor, etc. I found the solution to a similar problem with my previous MH this way. In my case it was plug wires putting on quite a light show but could be any of the ignition items.

Along with the above stuff, check your header bolts.....Dennis