There's a book called "The Used 911 Story" from Red Line Service that will help you out. It's $20.95, or was when I was kind of thinging about looking for a 911. It was recommended to me by a few guys on the renntech list.
Red Line Service
720 Colorado Blvd.
Santa Monica, CA 90401
(310) 450-7414
I never ordered the book, but it came highly recommended. IIRC, amazon.com only sold used copies of it, and it was published in the mid 80s or something, so I don't know if you'll be able to find it very easily.
There are a few websites that explain the differences in model years, and what to look for. If I remember what they are I'll let you know.
Bob
