i'm sure an ole' walbro will go into the tank. and you could probably adapt any install kit. looking at my install kit for the one in my probe. it would be simple to adapt it to anything.
best way to break in an engine is to get on it within the first 20 miles of its life. not too hard, but give it some nice revs and what not. then change the oil. i forget the site, but there is a guy out there that has a story on it, and it makes perfect sense.
i have no problems with spike with my EBC. with an EBC, there is usually something you can adjust so that it does not spike. like the Gain and Start Boost with my Greddy
not even a VJ-11. i have a VJ-11 on my probe. and i know the GTX compressors are smaller. what i would do, is take the turbine and get a 87-89 thunderbird IHI compressor (vj-17) thats a very nice, fast spooling turbo good for up to 20 psi.