Welcome to TRS
Yes, that would be an odd swap
Rangers had two different 4.0l engines, OHV and SOHC, VIN X and E respectively
And there were two 3.0l Vulcans, gas only and Flex fuel, VIN U and V respectively
Ford cars use different engine VIN numbers so you have to look up TRUCK VINs to see correct engine size
But to answer your question, no, a 4.0l transmission would not bolt to a 3.0l Vulcan engine and visa versa
The transfer case will bolt to any Ranger 4x4 transmission, all the 4x4 tail shaft housings had same bolt pattern
The bell housing patterns are different based on engine size, for the most part
The 3.0l Vulcan is a high RPM engine by design, it makes best torque at 3,500-3,900 RPM
Most engines do that at 2,500-2,900rpm
So if you drive it like a lower torque RPM engine then you WILL BE disappointed
This engine likes and NEEDS high RPMs, so "drive it like a rented mule" as the saying goes
Remember under 3,000rpm you are BOGGING this engine down
It would be the same as driving another engine around at 1,500-2,000rpm and complaining it had no power
REV that baby up, you will NOT break it, lol
Info on the 3.0l Vulcan here:
https://www.therangerstation.com/tech_library/3_0performance.shtml
Look at the torque and horse power RPM numbers
And yes, the 32" tires don't help, they are heavy of course, but they also lower the rear axle gearing by default
Go here to find out what rear axle ratio you have:
https://www.therangerstation.com/tech_library/axle_codes.shtml
Look on your drivers door label
Also look at stock tire size on that same label
Then go here:
https://www.therangerstation.com/tech_library/Gear_Tire_RatioChange.shtml
That will tell you "actual" ratio with larger tire diameters
Lower ratios are for better MPG, higher ratios are for better power
With a 3.0l you want 4.10 or higher no matter what, that keeps RPMs higher in any gear