I have a 390 cfm holley vacuum secondaries carb on a 4 bbl Offy manifold, Clifford headers, 264 duration .444" lift cam, head milled .100 and porting. Any jetting suggestions would be appreciated.

wow,been a long time since i've been around this or anyother slant site Start with 64 up front 66 in the rear and work your way from there. from the experimenting i've done i put a 2" 4hole spacer on an offy intake and had really good fuel distribution also, but made it run alttle more lean. picked up .2 - .3 from the spacer alone!

-the hated one

I have some metering plate instead of secondary jets. I s ther any way to get rid of this?

You can get an adapter to replace the metering plate so that you can use standard jets. Jegs has 'em. They also have a metering block that does not use jets for the primary side; it uses adjusting screws.