I have a 1992 Ford ranger and trying to find the best engine in it it has all original part besides the engine which it has none at the currently moment

 

good time for a 5.0

 

The easiest motor to put back in it would be another copy of what it last had, but the best motor for you may be something different. Anything is doable but the further you stray from one of the factory options for this vintage truck the harder/more expensive the swap.