Well, I've finally got the 2.2 in the 99 OBW, and it was really easy. A few thing I found:
The power steering hoses are a bit different, the 99 OBW lines are positioned 2 or 3 inches more towards the right of the car than the 95 hoses (bigger heads on the 2.5.) Everything fits, but the mounting tabs on the hoses don't meet the mounting points on the 2.2. Using the hoses from the 95 would be a good choice, and changing them with the engine out of both cars would be pretty easy (but I didn't.)
The lower starter bolt hole in the 95 bell housing is threaded for a stud, and the 99 OBW bell housing is not threaded, as it goes to a hole in the engine (for a engine/trans mounting bolt.) I used a 1/2 inch tap (what I had, not what I wanted) to tap the bell housing, and drilled out the lower hole on the starter to take a 1/2 x 1 bolt. Works fine. I considered welding a nice metric stud on the end of piece of 1/2 bolt, but I'm lazy. A metric helicoil would probably work even better.
The 99 OBW exhaust fits perfectly, as does the radiator, fans, and all of the cooling system hoses.
I used the 99 OBW crank pulley, as the one from the 95 had a bunch of rust inside, and one from the 99 looked new. They are different looking pulleys, but the diameter, sheeve spacing and bolt hole depth are the same.
I ordered an oil pan from a junk yard for the 2.2 (old one was really rusty,) and it looked just like the oil pan from the 2.5 out of the OBW. It was indeed a different shape than the pan from the 2.2, but bolted up perfectly, and the return and dip stick tubes matched just fine, and and it looks like it may have a touch more capacity.
I also used the oil seperator from the 2.5, as the 2.2 had a plastic one which was leaking.
Thanks for a great board, and I've got to go watch the race going by a block from my house.
Pat