Have a 1991 honda civic hatchback and i wanna know the best engine swap for cheap?

Have a 1991 honda civic hatchback and i wanna know the best engine swap for cheap?

Cheapest motor I would suggest is the b18a/b (base model Acura Integra motor). It's a cheap starting point with a lot of upgrades available if you want to go fast plus there pretty reliable if you want to stay stock.