A thermoquad can be the best of both worlds, IF you can find a good one. I will also note, that in MY experience, mopars tend to be pretty tolerant of overcarburetion, compared to sbc
This. A TQ is a great carb,has small primaries for cruising around and getting decent economy,and mother of god huge secondaries that gulp huge amounts of air. Chrysler felt 800 cfm TQ were fine on theit 318 cop car motors with 360 heads. Reason being the air door over the secondaries is vacuum operated and works on demand from the motor,so it will only ever get as much as it wants.
And it's why rustyratrod is right as usual. Any given motor will respond differently depending on CID,and believe it or not,the type of trans (manual vs auto) has some effect as well.
For an automatic trans car behind a 318,something like a 600 to 650 cfm vacuum secondary eddie or Holley would work great.
