[Guest]

Ever since I took my '68 J Code (302) out of storage it backfires thru the exhaust on deceleration. I have a pertronics ignition. Is the timing too far advanced? How did it change?

 

[Guest]

Check for breaker plate bind and/or vacuum canister failure.

 

[Shelby1308]

Also take a look to see if you have any exhaust leaks.