Yeah, it's a simple calculation on the piston area. Pi r squared.
From what little I do know in basic physics, if you apply pressure more evenly at two points across a flat surface (brake pad) then your overall stopping power should increase, when compared to applying that same force at only one point on the same size surface (brake pad) - but piston size (area) difference will definitely affect that when using the same master cylinder to apply that force. Applying force at only one point, you also certainly have "some" deflection of that brake pad, even if it's a very minute amount. More even clamping is bound to increase stopping power overall. Ford obviously went to the dual piston for a reason. The ever-increasing goal of shorter stopping distances. Perhaps more even brake pad wear as well. Only their engineers know for sure. But I'm sure that master cylinder and proportioning valve differences also play a role in the total outcome.
"The 1st gen calipers are a single piston 2.625" diameter. The 2nd Gen are dual piston calipers with each piston having a diameter of 1.811"
I'm definitely thinking I'll have to convert to power brakes to take full advantage of this swap. Which sucks because it also involves swapping out pedal components or the entire pedal box, which I don't have on any of my parts vehicles. None of my Ranger or Bronco II's had a manual trans with power brakes. So I'll have to look in to being able to swap only the brake pedal lever itself. I'm not well versed in this area, other than fabricating and adjusting clutch pedal stop.
Motor Trend listed the 83 Ranger 2.0 standard cab long bed, 55mph to zero stopping distance at 127ft (look out, she's coming in hot!! lol)
Motor Trend listed the 86 Ranger 2.9 extended cab shortbed, 55mph to zero stopping distance at 135ft
Motor Trend lists the 98 Ranger 4.0 XLT extended cab 4x4, 60mph to zero stopping distance at 147ft (overall weight surely adds lots of distance here)
https://www.motortrend.com/cars/ford/ranger/1998/1998-ford-ranger/
Motor Trend listed the 95/96-ish Ford SVT special project Ranger having a 60mph to zero stopping distance of 148ft (having all wheel discs from the Explorer and a V8 up front, as well as having 255/45ZR17 Goodyear Eagle's up front and 285/40ZR17's out back.) <-- that's identical to my 87 as far as engine weight and tire size/width, but my truck is lighter overall.
https://www.motortrend.com/news/ford-ranger-svt-v8/
"Great rubber can make a big difference in the turning and stopping performance of any vehicle, but it can't overcome poor weight balance. Remember, this is a pickup. They're inherently tricky when it's wet or icy and there's no load in the bed, because most of the static weight (in this case, 2204 of the 3554 pounds) is concentrated over the front wheels. With an iron-block V-8 in a compact truck, the problem can be intensified. Despite this condition, the SVT Ranger posted a respectable best stop of 148 feet from 60 mph-thanks mostly to the four-wheel discs and the anti-lock electronics stolen from the Explorer."
So it looks like it'll be anyone's guess if I can actually get my little 87 to stop better doing this 97 beam/brake swap. Converting to power brakes would certainly help, I'm sure.