I've seen multiple cars where the gears made more noise than the exhaust did and accurate did the gears. Im buying my gears from buyfordracing.com FRPP 4.10s are $140 shipped. I just need the install kit, I know latemodelrestoration makes a couple and so does CJponyparts.
Here's a better question maybe, what are the parts I need to do a gear swap other than gears and a rear end?