Classic/Antique Car Repair: backfiring mustang, rust free, gas filter

Question
I have a 1968 mustang with a 289 v8 4 speed.

The car backfires often, especially when I coast at a high rpm.

I just got the car, a rust free arizona beauty. but it hasn't been driven in some time.

Thank you

Answer
Eric ;
  HI - well if it has been sitting for some time it could be a few things, it  could even be the fuel.
I would get a can or two  of some dry  gas and add it to the gas tank.and you could even throw in a can of carb / fuel tretment  just to clean out the lines. than I would change the fuel/gas filter. also get a oil and filter change. Than I would have a good tune up or at least check everything, this way you will know what you have in there. as far as the back fire it might be the gas or a bad plug or wire, cap, rotor, etc . so I would have a good service done to it this way you will have it all running good and nothing to worry about.  ok .....>>>><