Good luck man. I'm in the middle of doing this myself, and the devil really is in the details. All the little odds and ends that nobody seems to mention, and add up really quick.
Especially if you plan to stay stock. When people say it's easier to go single right off the bat they are not kidding. Also if you have the MKIV vs. the Aristo engine can make a big difference in how much trouble you run into.
example: The water neck on the Aristo sticks out farther than the MKIV version creating clearance issues with the fan.
The oil return elbow on the Aristo is angled for the front sump pan. When you put on the mid/rear sump pan you have to change the two 4in. sections of hose that connect to the elbow. and even the it places these sections of hose at extreme angles, and stresses that may shorten there longevity/reliability. That elbow can work but the best solution would be to get the MKIV turbo oil return elbow.
For the intake side the BIC mounts interfere with the intake manifold support brace. The brace has to be removed and two vacuum hard lines are riveted to it, that have to be drilled free.
On the exhaust side, my 87 engine mount(Not the BIC metal half, but the square rubber) interfered with one bolt on the Y-pipe coming off the turbo. You may not have this issue as your car is a 90 with the round mounts.
For the aristo motor, when your change over to the rear/mid sump oil pan the oil stick has nowhere to bolt to, a custom bracket has to be manufactured.
Those are just a few of the issues I ran into, there have been many more.
You may not have an aristo motor, so it may not mean anything to you.
