340 383 4bbl used same bar, 383 2 different, 440 426 used same bars. 920 will work fine, we had 960 in a 440 six pack cuda and it road like a truck, too stiff. swapped out and put the 920 bars in and it rides great, 960 in our hemi car and its a little sponge for my liking, may upgrade those to a 1 incher.
i have 2 sets of the 920 bars in stock new mopar if your interested.