I had the points and condenser replaced about a month ago, as well as the carb needles cleaned and carb tuned. Drove around for almost an hour today with no trouble, but when I pulled into the driveway and put her in park, she revs and ticks. "rev tick tick tick, rev tick tick tick." The rev reminds me of my previous surge and stall problem, but it's not as strong of a surge, and if I give it a little punch of gas, it idles normally for a while. The ticking seems to be coming from a metal piece attached to the rear lower corner of the engine block on the passenger side, which isn't attached to anything else, and moves when it ticks. I don't know what it's called or what it does. The shop manual makes no mention of it. Is this purely a carb issue?