The most common Holley 390 is list #8007. Many circuits are either adjustable or replaceable, except one: the full throttle mixture.
But isn't that supplied by the main jet? That is the only circuit for high vacuum cruising, and if you increase the MJ size mileage goes down.
But it doesn't supply all the WOT fuel, the remainder is supplied by the PVCR (yours is probably .038" now), and the adjusting tool is a drill.
Last edited by panic; 05/06/2018 7:14 PM.
