Hi House...,
You've been a member 4 yrs.+ now... You'll be better served if you fill-in your sig. & profile. i.e. receive accurate info./help.
"I probably have only about 1.5 - 2 in."
Have not heard of this lift...
Is this lift homemade..?
Most lifts start @ 2.5" & up fr. there. The actual height of your lift would be an important 1st. step.
"should I go with the 2 or 4 degree C-bushing kit"
Unfortunately, there's no clear-cut answer here as it seems every lift/bronco is different.
For example., I had to re-do mine to 7deg. even though I have a 2.5" lift., in order to get the proper caster.
Normally it's 2deg. stock., 4deg. for a 2+" lift., 7deg. for 3.5"-5.5" lift.
"after replacing do I need to have the front end alignment checked?"
NO.., there is no adj. The "toe-in" adjusts but you won't be moving that to change the "C"-bushings. "C"-bushings move/correct the caster..., the camber is pre-set at factory @ 1deg.
However., it doesn't hurt to "check" it on an alignment rack so as to get the good news (hopefully) that it's with-in spec.