I wouldn't. The 80s M bodies are known for their notoriously weak 7.25 rear end they used in those cars. You really dont want to do anything to put any extra strain on them like towing a trailer or racing, or you're at very high risk of shearing all the teeth off your spider gears. Even driving in winter, where one wheel is likely to spin faster than the other while slipping on ice, will quickly eat up those spider gears.

Unfortunately, unless you want to swap in an 8.25 rear end from a 70s one, you really only want to use the cars as grocery getters and commuters in the summertime. Using them for utility or in the winter months is just asking for trouble. I had an 85 fifth Avenue once. I drove it in the winter 1 month and that was it. Total rear end destruction.