Interesting cars! Not quite as bad as Ralph Nader said that they were but they WERE different! My former-brother-in law had one also in the early 1960s but I don't remember the Monza's model type...

The Monza spyder I think was the sport model it was a lot of fun I owned a couple Corvairs they was the hard top SGT Mark Anderson

SPC Michael Oles SR - The Monza Spyder was the sport model of the
Corvair line and had the engine with the higher HP. My buddy had a Spyder with
a 4 speed transmission and ran it on a competition road course. Lots of driving fun.

Excellent!!