1980 Pontiac Firebird Formula

This is a 1980 Firebird formula. I bought it from a garage where i was told that the engine was replaced with a 455 pontiac engine. The car starts right up every time with no problems and idle good, ut when i press on the gas i get a backfire. The floors are in good condition, he trunk is solid. The interior is in decent condition. The dash is cracked, nd there are a few tares in the drivers seat but the others are in good shape. The door panels are in good shape. Has inspection on it. Needs trim on the back window. Has some rust but this car is a good canidate for restoration. Has rust in the wheel wells. will probably need new tires and brakes.needs exhaust The choke light is on .86,834 on odometer. I have a clean title VIN # 2V87WAN101536. I am not a mechanic and I am describing the vehicle to the best of my ability and is being sold as is. The buyer will be responsible for shipping/pickup of the vehicle. Cash or cashiers check.