I haven't been to any MoPar-only shows in a few years - all are pretty far away from me - but I've been to Spring & Fall Flings, Las Vegas & Carlisle in the past.

Spring Fling seemed bigger & better than Fall Fling, which was still pretty worthwhile.
Vegas seemed to have a lot of the same everything as Spring Fling, though Vegas' swap meet stuff seemed higher-priced. Bonus: drag racing & more race vendors.
Carlisle was simply gigantic, a 2-day affair just to walk through & see everything, lots more rare stuff & more incredible cars.