We "fixed" our "overheating" and non-working tachometer problem last night by grounding the gauge cluster better. However, we then noticed that the gas gauge was no longer working. We pulled that ground off again and the gas gauge returned to normal, the tach went dead, and the temp gauge shot up to full hot! WTF??
Well, we loaded up the car on the tow dolly anyhow and went down to our local "test track" (empty biz park) at ~11:00 pm and had a blast! The car is running great and is really zippy! (I won't say fast...) I can't wait until tomorrow when we head to Thunderhill Raceway for testing!