Just put a spool in it. I have driven a car with a spool or back in the old days welded spider gears for 1000's of miles on the street and never had any issue rain or shine.
See post above , year round driver and it gets driven during SNOW storms, a spool would be the best option if he went with a 9" instead of the 8.8 when I talked him into buying a spare rear for the car for just this reason, he hurts them somewhat yearly and clutch types required yearly rebuilds ...
He had a spool in a previous car , but that was a restricted use car that was driven sparingly on the street.
