so far.. of the parts you have named , only the steering parts are sn specific, .. becaus ethey are steering box specific.
thus you look at your steering box. if it has round covers.. it's early. if it has oval covers it is late.
most of the other sn changes involve the distribuitor type ( thus block type ).. since you have a 9n / 9n block.. all your stuff is front mount.
past that.. you will see axle seal issues based on early or very very late trumpets.
you can look at trans shifter, hump in the tranny.. date codes.. etc.
no mystery here... ez to figure out.