Hey,
The cat bolt pattern is the exact same so is the head bolt pattern. The only difference is that the new prelude lower section is a little shorter. All you have to do is weld an extension in. 8 3/4 of an inch works perfect. I have done this for fitting H22a4 down pipe on an h22a1 and I put a h22a1 greddy header on and H22a4 so I have experiance here. Any muffler shop should be able to take care of you.
Josh