Tuning Issues

[webman12]

So I swapped in a 360 this weekend. Put an edelbrock intake on it, edelbrock cam, and a qjet on top.

It idles great, right around 900 or so ( a bit high).
when I accelerate though, punch it and it backfires through the carb. Too much backpressure?

Is this a timing problem or a carb tuning issue?

 

[hole]

Timing. Was the distributer already on the engine or did you install it?

 

[DIG]

I had this same issue one of my 5's, I reset my timing and it ran great! reset your dizzy and put a timing light to it