Yes it will fit a 20R. The only diff between a 20R 22R and a 22RE exhaust is the R heads only use one bolt in the center while REs use 2. Nice header. Heck man I would try a few diff smog places and see if any of them will even ask for paper work. I know a buddy of mine has a header on his without a car stamp or paper work and he was never asked bout it since the smog and o2 were all located in correct place and intact. Just a thought.