On my stock 74' with a vac adv. dist., I've got a bit of a sputtering/slight gurgling sounds from the tailpipe at idle (uneven sound from the tailpipe). Under the hood, she sounds nice and idles at 650 or so and drives nice, too. My question is, what should I look into to tune out this problem? I'm feeling like it's a timing/vacuum/fuel....type thing, but not too sure. She's pinging a little bit doing the high gear low speed, 'step on the throttle' test, so I believe I need to retard it a little, right? Thanks guys.