John (Bongo577):
I have worked with Marc Haibeck on three separate ZR-1's and will testify that he is well worth the trip to Addison for work, repair or enhancements. I am in the Okemos (East Lansing) area and I have gladly driven my cars to him for diagnosis and problem solving.
I have also spoken to Ken Lingenfelter about working on the cars, since he has Graham Behan working with him. Ken advised Graham may not be the one working on the car, but he is still a great resource. Lingenfelter's shop is about a 45 minute ride from my place. Luckily all is well with my ride, but it's also a '91 with 120,000 miles so you never know.
I hope to meet up with you some day. BTW do you have pictures of your car to post?
