| usually there should be heat shields on the manifolds to deflect some of the heat off of the plug wire however they may be missing but it should be corrected if its already damaged the new wires.
if equiped with an egr valve you might try removing vacum line going to egr valve and test driving to see if problem goes away this valve is bolted to the intake and will have a vacum line going to it and will be on the passenger or right side of the carb.
another thing you can check is to unplug vacum advance vacum line and test drive and see if problem has went away if it has likely a bad pickup in distributer assuming the timing is set at 6 degrees btdc.
does it backfire out of the exhaust or the intake? |