first, the diffs are notoriously noisy according to the mb buyers guide. personally i dont think so. are you sure yours is unusually noisy? these diffs are extremely durable.

if you take the decision to change it note that the 2.88 diffs from 85 and up are matched with an electronic speedo gizmo and wont work in your 84. a 380 gas car comes with a 2.65 i think and they have the mechanical speedo that will work for your car. this will give mileage improvments and less engine noise at road speed but will make your takeoff more doggy.

lots of recent posts regarding these subjects.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.