Father-Son 1974 Duster Project

No wonder I couldn't see my timing mark with the plain timing light. I had 50* of total timing! lol
I set the initial at 20* and total is 32*
Real nice lumpy idle now but as I rev it still falls apart almost like a rev limiter or something. @AlV thinks it's ignition not carburetor. I think so too. I have a spare HEI module I can put in to see if that changes things. Timing does not dance around except when at 500-700 rpm it fluctuates slightly. It stays steady when rpm rise. I'm wondering if the pickup in the distributor may be bad. It's a stock replacement remanufactured Mopar distributor. I'm hoping @TrailBeast can offer a suggestion.