timing question

Close. I think it's more like 5 btdc. Best bet is to look it up for your specific car as they did vary. I always go a couple extra degrees on a old engine also to help performance. Just watch for spark knock and back it off it it spark knocks. Attaching the vacuum advance line should not affect idle speed cause it should be connected to a ported vacuum source. If it does change when you hook it up it's hooked up on the wrong port on the carb. No need to gap the plugs wider. Mopars always used .035 for the gap whether points or electronic. If you have a MSD with a high perf coil you might be able to gain some perf. by gapping the plugs a little wider but not with stock ignition.