lowest static drop for my chevelle

[okyankee]

hello, my 65 chevelle is my first project car. i am used to trucks. lifted and lowered. with the stock frame, how low of a static drop can i get? it will be mini tubbed for sure. not sure if i will just buy a rear clip or reuse the ones they chop off. probably buying one really. i would like to fit a 20x10 or 20x12 wheel on the back. but most i seen only run 18's. i figure with enough metal work, a 20" wheel would fit. correct? i think 18's will be on the front. thanks for any help. this whole thing isnew and scary at the same time.