@Tranger1988 ,
A stock 2.9l can run pretty good on a single 2¼" exhaust. If you contact the manufacturer of your muffler, they can tell you the best size tubing to use depending on engine displacement and power output.
If you call Borla and tell them that you are using 2 ProXs mufflers with a 140 HP, 2.9l v6 and ask what size tubing to use for true dual setup, they will do the math for you.
The original "H" pipe that connected the exhaust manifold to the cats was 2" O.D. and appears to have been incorporated for the use of a true dual exhaust. A 2" true dual exhaust is big on flow volume for a stock 2.9l but the real challenge will be to stuff it in there.
The real estate available to place two tubing runs are no dought the REASON that 2.9l era Ford decided to use a single tube exhaust on Rangers and BroncoIIs. Even the 2.9l equipped Scorpio used a single exhaust.
In regards to the use of the Cherry Bomb mufflers, it usually boils down to a person's choice in sound but I have a different skew on this. If I'm going to take the time and money to fit a dual exhaust system into one of these trucks, I only want to do it once. I recommend using stainless steel mufflers and tubing; I am partial to the sound of Borla mufflers and they make a great product.
If you are set on a cross flow, Borla makes a dual in/dual out muffler in 2¼" (called Turbo XL but that's just the former name for the current ProXs model) that could be used with 2" tubing with modest adaption for a true dual 2" tubing system; that is what I would use.
Another company that I would use is Magnaflow. Ford uses a similar muffler, though a bit larger on their 2014-2017 Explorer Police Interceptor Units; it would be a much cheaper way to go about it, using a wrecking yard pull. It is long though, it looked like a solid 24" long. This PIU exhaust is a 2" dual exhaust, from the wrecking yard should only set you back $50-$60 for the entire mid section (marked in yellow or just the resonator (blue arrow).
Welcome Visitor! Please take a few seconds and 
