Technical 64 Chrysler 383, , Torque flight questions

If all else fails check the oil pressure and compression pressure. Oil pressure should be 40 - 65 PSI and compression at least 140 probably more, but in any case all cylinders should be within 15 pounds of each other. Low compression and low oil means a worn engine. But if it checks out good, and the timing chain is good, it should respond to a careful tuneup. Adding more carburetors won't fix a worn out engine.

 

As said by others, engines are like people,temperatures affect them differently. I have made a lot of money in both northern and southern states removing intake manifolds and chiseling out carbon plugged crossovers(due to short trip driving))on "stumbling pig," when cold mopars. If you want to experience carb icing get a can of choke cleaner and spray it on your finger on a 80 degree day. This cold spray is what happens in your carb, (atomizing fuel). A working crossover,among other tasks prevents this icing.
If your wife uses the car you might want to consider a working choke crossover ,when crossing intersections or rail road tracks.
I have never seen a Mopar with a crossover not have unburned paint in the choke well area area.