I have decided to give the GM TBI a shot. If it fails, I don't have much invested, and I can easily fall back on the Howell. If it works, I can say I did it (with a little help), I will definitely learn something from doing it, and it will certainly save me a few dollars. Today, I finished machining the adapter plate, and have started cleaning up the wiring harness some (not cutting, just cleaning). I have a good friend whom I am sure has rebuilt some throttle bodies. I think tomorrow I will go have a talk with him and find out what is involved in doing that.