I disconnected the exhaust elbow (the piece coming out of the engine) and the mixing elbow (the piece it connects to) and brought them home. I tried to salvage the non-cracked pieces by trying to clean the 30 year old gunk off of them to no avail.
I called mechanics and went to marine service shops but nobody had the parts. I was going to order it through them and pay the hefty price but they were very slow to get back to me. They only care about the half million dollar yachts they service, not my few hundred dollar purchase.
After doing some research, I learned the part numbers of the pieces I needed.
104214-13521 mixing elbow
104211-13070 exhaust elbow
104214-13580 adapter joint.
This document really came in handy. Click here.
I found a great online store that carried all the parts, and ordered them. If you are in need of some boating equipment and parts, check out shop.torresen.com