Bingo!
On the mainland USA, AFAIK, the 400 only came with a 4bbl carb being a TQ in which i highly recommended the larger primary TQ.
For a street 400 engine, no more than 9.0-1 if it needs the rebuild (and it probably does) a TQ carb if possible on top of a performer intake if the factory intake is not available exhausting through standard headers into a 2-1/2 H piper exhaust.
