Carb for my 318



Your wrong in the way the that the 1405 is simply jetted richer while the 1406 is jetted lean for a chevy.

That is a mixture diff and wether it gives more performance or not is based on the engine a/f requirements.

They still flow the same.

Chevy ? What ?

All I stated was a 1405 is calibrated for performance,1406 is calibrated for maximum fuel economy. That is a fact. Pick up a book and :study: