I have helped some people fit their Kadet, and the first time I made it so tight it was a PITA to swap uppers.
JJ:
The fit on a 75 KADET had little to nothing to do with its accuracy .... not a thing !
It can be a tight as you can deal with, to Field Stripping it
OR .... it can be as loose as a Spanish 1911 .... makes no difference
Since the Sights are (basically) fixed to the Barrel, almost as if it was Iron Sights on a Rifle; so make your Kit fit as well as you feel is best for you !