You can get a late model 4.0L OHV and auto trans and swap it in. Ford used the 4.0L OHV in the ranger, B4000 and explorer until 2000. The heads were updated heavily in 1995. The 5r55e automatic can be built up to be a nice strong smooth auto trans. You can use the engine with the later model OBD2 computer and wiring, basically converting your old tired V6 to the updated model with a stronger more efficient 5 speed auto
You can convert to a 5.0L V8 and get a 1/2 ton transmission. Putting the 302 into the Gen I (1993) requires a few parts and tricks, like tucking or hacking the radiator core support, relocating the oil filter, and sorting out what transfer case to use if you are 4x4
I know a few people here who have converted to the sohc engine into the gen I trucks, but in my opinion it does not fit as well as the 302 and it is/can be just as much work and cost, you are still left with the V6 auto trans at the end of the day
There is one conversion I do not see very often anymore, but its a dang reliable setup. You can refresh your current 93 4.0L engine (or replace the block with a later model one) and then run a C4/C5 automatic.. they are tough as nails, but only 3 speeds
Also there is a aftermarket adapter to run the Chevy 700r4 automatic behind your OHV 4.0L, I am not sure how viable that option is, it has been years since I looked into it
The V6 option is cheaper and easier then the V8 option but the v8 option is pretty awesome when you are done
Do you have a budget in mind?
What do you plan to use the truck for?
If you are 4x4, what transfer case do you want to end up with?
Welcome! Don't be afraid to use the search bar, there are quite a few Gen I trucks that get built up around here
