All depends on budget and how frogy you are.
Most common is a m113, but also been a 4g63, LS and a hemi conversion.
I say go different and use a duramax
LS does have a huge aftermarket support and a all aluminum flat plane v8.
Just wish there was some options for mb engines at a descent price beside custom made.
Even be nice if we could code a pentastar v6, then could have a all aluminum turbo v6.
Well be nice if we could code the mopar ecu to accept our dash and cruise control, but wishful thinking.
But anything will fit and work if you spend enough $$$$

Give a budget and some could give you possible options or give us a laugh.