Kind of long story.
Car sat for at least 5 years. Owner tries to start car with 5 year old gas. almost gets it to fire many times but , well...5 year old gas.
I get a call. I take the Carb off, clean the fur out of it. drain tank run some new stuff through the lines. Put Carb back on and car starts, and idles BUT sporatically it backfires through the exhaust ..Pretty loud. doesn't do it above about 1200 RPM. I'm thinking either Fouled plugs or maybe sticky valves. It is only doing it on one side of the car (Dual exhaust). I didn't pull the plugs because The manifolds were HOT from letting the car run for 15 minutes. I also didn't bring tools with me to pull the plugs and clean them.
Any thoughts? Plugs, Valve or ??