I don't think plugs are to blame for a backfiring problem, I would look elsewhere for that. It could be a number of things (computer problem, fuel delivery problem, sloppy timing chain, burnt valve, etc.)

Unless you are running Nitrous or a blower, the stock gap should be fine.

I don't have Edelbrock heads myself, but, many of my friends do. They seem to work well with the Autolite 3924's.

 

Yeah what he said. I'd look at the timing, fuel pressure and fuel injectors to figure out the backfiring.

I use the 3924's in my Edel. heads, 6032's, but I gap them at .035 for the nitrous, .050-.055 on motor.

 

Since you all have seen the Edelbrock heads perform, would you happen to have a flow sheet or know how well these heads flow?

When I first got the car, it ran without backfiring for a month and then it started. Someone was saying that one of my spark plugs may not work since it is running really rich. Does that sound right?

The car really needs to be tuned and I'm sure that'd help a great deal with the more gas than air flow into the motor.

Here are the mods if you are wondering, they're in my sig.

Corey

 

You could definitely pull the plugs and take a look. If the car needs a tune-up anyway replace the spark plugs, cap and rotor, wires if it needs it, check the timing and the fuel pressure and see if you pull any codes. If you do all this and you still have a problem, post up again and try to be specific as to where your having the problems, (at idle, high or low rpm etc.).

If you do a search on here for flow numbers there's a couple links that flow several different types of heads side by side.