"I am an Engineer"- - - - - -You have my sincere sympathy!
Stick with the 4.11 rear end gears. You will experience some severe bogging on acceleration from moderate speeds with the 3.55 due to losing virtually all your venturi velocity anytime you attempt to pass, climb a hill, or haul any kind of a load bigger than an iced-down Yeti cooler. The only solution is to keep the engine wound up above 2500 RPM or so at all times. Even with the 216 carbs, you will be WAY overcarbureted. I'd suggest using a pair of Carter carbs intended for a CJ-2 Jeep 4 cylinder. They have the same throttle body footprint as the 216 carbs, but two of them will get you into the ballpark CFM-wise and mimimize the tendency to bog down on acceleration. This discussion has been playing on an endless loop for the almost 20 years I've been on the stovebolt site, with the same results. Most people invest tons of time and money only to get a mediocre increase in performance, mostly at RPM ranges no sane driver wants to run on the street, and lots of low speed and midrange RPM gremlins to play whack-a-mole with.
However, dual carbs and a set of repop "Fenton" headers impresses the heck out of the mouth breathers at a "show and shine" who don't know any better. Good luck!
Jerry
