95 buick riviera engine

i just aquired a 95 rivi with the 3800 supercharged with a locked engine. what i need to know is can i switch to the regular 3800 for this year or from another vehicle. i really dont want to put a supercharged one back in unless i have to. i really just need it to run. someone let me know what i can do,im trying to limit the cash i put in to it