I am doing a budget build over the next year on my 88 camaro. I am going to drop a 350 TBI into it with 350-400hp and am looking to get the entire car ready for that so nothing is breaking the first time I mash the gas

So the question is what the cheapest route I can take for a rear that can handle 450hp (to be safe). Obviously I wanna go posi and because its and everyday care I was thinking 343's. I'd love to just be able to pull a rear out of the junkyard and not have to build it since I dont know anything about rear ends. So what wrecked car could donate me that rear?
PS: No fab work just drop right in and I'm flexible on the gears.