Welcome to the forum
You don't want the 3.0l Vulcan engine as a replacement, sell it, and use the money to rebuild your 2.9l with 1989-1992 heads
Or
Get a 1990-1994 4.0l Ranger that's rusted out but still runs
The 2.9l became the 4.0l, so 4.0l just bolts in, same motor mounts and same transmission bell housing
But you need the computer and engine wiring harness, along with some engine bay parts(all of which you would need for a 3.0l swap, as well)
2.9l is 140HP
3.0l is 145HP
4.0l is 160HP
3.0l Vulcan was a very reliable engine, no question about that, but under powered for its time
4.0l OHV is also very reliable, and has better power, and torque
If you really want to use the 3.0l then find a 1991-1994 3.0l Ranger that you can get engine bay parts from and computer and engine wiring harness
Also need the distributor and spark system if your 3.0l was a 1995 or up model
AND.......3.0l transmission and motor mounts
Trans need to match manual or auto, and 2WD or 4x4, what you have now in the BII, I think BII all were 4x4 transmission even if its a 2WD, they had the empty transfer cases