OK, I did the same thing for my jeep....I bought a stock '96-2000 vortec long block
for a truck with the idea of using a brand new vortec injection unit that I bought on the bay. I gathered a stock GM Vortec ECM and sent it to Fuel Injection Specialties in San Antonio TX to reprogram for my 4:56 gears and 37" tall tires (back then, now 40"). They also made me a nice harness for the engine/controller. As I worked thru the project, the stock vortec controller had several limitations that proved to be a pain....stuff like VATS and the upstream/downstream oxygen sensors on two cats. After seeing this would get really complicated, I stopped the direction that the project was going and went to a fuel injection system from Arizona Speed and Marine. They used a GM vortec intake, welded injector bungs in the proper locations and topped it with an MSD air meter. The computer is a MEFI unit. It required the proper MSD distributor (for a fuel injection engine) but, when we got it all together and turned the key, it fired immediately and has run great ever since.

We are in Tucson at 2700 ft and the jeep has been to about 12000 ft in Colorado without a hiccup....FI is great, I can be tilted sideways at 45 deg and the thing runs.....the FI cost me about $3800 with the harness, manifold, injectors, air meter and MEFI. It idles great.

mike in tucson