[Bearhawke]

Thanks, this is great information. So, a TQ carb from a 1972-75 400 (pre lean burn) and an aftermarket kit should do the trick? (hopefully). The CFM on the carb should be 650 or so?

Yes, that would work. You can make the carb on there work, but that's a lot more hassle than replacing it in my opinion. The earlier 400 Thermoquad is probably tuned for a little more stout engine than yours but I'd bet it will fine.

Too; pretty much any non Lean Burn TQ will work on a stock 400, even the 1980's 360 V8 applications.