Edelbrock Performer OR Stock 73 Intake on 340
The Performer 318/360 isn't the manifold a RPM or Air Gap is but it's no slouch either.
Seen some 360's with 275hl and 9.5:1 make 400+ with a Performer, actually up to 440. Will a stock 340 do the same, likely. Pick your poison and maybe open up the port window a bit, window size in this case is overrated as to effect, and the performer will work well.