What Engines will fit a 96 buick regal custom?

i need an engine for my car but im having trouble finding a buick regal engine. so i wanted to know what other engines would fit on it.What Engines will fit a 96 buick regal custom?If its a 3800 you can look at Bonnevilles, some Grand Prix, Park Ave, lesabre, 98's, and some of the vans like the Transport and whatever the olds one was called.What Engines will fit a 96 buick regal custom?5.7 v8. you'll need to get a different transmission. but they make aftermarket motor mounts.