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If it developed a tick at the same time, my first suspicion is valve train. Poor man's power balance test take the girdle off the plug wires. Engine running grab a plug wire a couple of inches from the distributor cap,wiggle and pull up until the wire comes off,listen for the idle to change. Repeat until you find cylinders that make no change to idle. Test resistance on those plug wires,examine those plugs,run compression on those cylinders. If you have headers,which I'm assuming you don't. Instead of checking at the distributor you can wet a couple of fingers and just tap the headers by the ports,the cold cylinders are suspect. Both of these methods require a little common sense,so you don't get burned or shocked. You probably will get shocked a couple of times,it really doesn't hurt. Ignore this suggestion if you have a pace maker or medical condition that getting shocked might hurt you.
Might try disabling spark then cranking over. A cylinder not filling or low compression, starter will increase speed and be uneven on a bad cylinder. I used it many times diagnosing a misfire. Suggested what direction to proceed with diagnosis. If available hook up a vacuum gauge.
Ticking sound? You might have a sticking intake or two, in addition to vacuum leaks and/or partially plugged idle/low speed circuit in the carb.
