Here are 2 different 3x2 fuel injection system options.
If Dick B. can't get our Rochester Tripower to do the built 421 justice, the next step is 3x2 throttle body injection.
Naturally, my wife (it's her car) wants one that "looks like a Tri-Power" so that means $8,000 by the time all of the supporting parts are added to a $6,000 system. The F&B is the one that I only have a picture of, the link is to the more costly system, but looks like 3x2 bbl Rochesters.
http://autotrendefi.com/efi-2g.html
F&B is first 3 pics and is direct port injection.
Auto trend is LAST pic and look like Rochesters