Yellow6t7

Took the cover off my 67 (327/300hp) and went for a 1+ hour shake out cruise. NE weather was about 50* and sunny and road salt appears to have been washed away.
Had a small issue during the first 30+ minutes of my ride. Car was back firing a little while cruising along at 1800-2000 rpm. Eventually as I continued to cruise the back fires seemed to stop. Car ran great otherwise, idled fine, accelerated fine, ran a little cooler than normal though.
Could the back fires be cause by old gas? I did put it away with stabil mixed into the gas.

Frankie the Fink

Old gas or blowing a little crud off the plugs...
Put some fresh gas in it, maybe a little fuel system cleaner and dog it a bit and see if it behaves...

dplotkin

Was the backfire from the exhaust or under the hood? The former is more likely ignition and the latter fuel. I'm with Frank on what's next, but the source of the pop is a clue.

Dan

Yellow6t7

Pops were from exhaust,
Did get on it a little, but only to maybe 3500 rpm

dplotkin

Probably cobwebs, so to speak, if it doesn't repeat. If not take a look at and under the cap, the wires, etc.

Dan

Westlotorn

3,500 is a lot short of RED LINE! Of course you don't do redline if it is having troubles like backfiring.

3JsVette

Hopefully nothing more than a bit of a slow wake up from the winter hibernation.
I'm with Frankie. Some fresh gas and some fuel system cleaner and another spirited ride.
See where it goes from there.

Frankie the Fink

Exhaust backfire (some call it "afterfire") is fuel igniting in the hot exhaust pipe...most often it happens on deceleration (so yeah you wouldn't be hitting the redline..)

Sometimes its a simple as a loose exhaust manifold ...as you come off the gas engine vacuum spikes and draws in air creating a lean condition.

But try the suggestions above before you go medieval on the issue....

Yellow6t7

Thanks ALL,
Will try adding some fresh gas and see what happens.
You all made me a bit more optimistic .
Now I need the weather to cooperate, snow and rain today.