2022 edit:
The Corolla All-Trac (88-92, with oil cooler port) and AE100 Corolla / Prizm (93-97, no oil cooler port) 4A-FE oil pans will work with the 20v. The 7A-FE oil pans (2 piece design, upper = aluminum, lower = stamped steel) should also work since they also have that notch / cut-out on the oil pan & block.
My newer image above should also say that the early (88-92) 4A-F & 4A-FE blocks & oil pans are the rectangular design like the 4A-GE 16v.
Old content of my post:http://img.photobucket.com/albums/v375/ ... 784b50.jpgIn a word, no, the 16v and 20v oil pans aren't interchangeable.
You can use any 4A-FE oil pan with a 20v. I don't know if those 20v-powered cars came with oil coolers or not, because most 4A-FEs aren't oil cooled.