3D was all the rage in the early 50's. Columbia experimented with a pair of Three Stooges shorts in the summer of 1953. "Spooks!", released in June, was followed by "Pardon My Backfire" two months later.
This time around, the boys are mechanics who need money to pay for a triple wedding after being engaged to their girlfriends, a trio of sisters, for 10 years. The version posted by Doug Ward is the 2D model that has been used in syndication for decades.
In 2D, the gags don't project as well, understandably, and Columbia abandoned the experiment after this short.