twin turbo

i just picked up 2 turbos for free from a friend they came off a chevy . 2 garrett t04, and wanted to put them on my 383 in my 67 belvedere but not sure how to go about it. can i use them with a stock 383?? im new to forced induction so just looking for some guidance. the motor just has a mild cam and an intake..will the motor need to be built up? all help is appreciated. thanks anyone have threads on theyre twin turbo big block builds not tryin to spend a crazy amount of cash . also how much hp would each turbo add?