1978 Camaro Wiring Diagram Rpm Tach - The Rear Axle . Contributed by John B (vegadad) Reference: Building the V6/Vega by John Thawley. Over the manufacturing life Of the H-body, several Gear ratios were offered in either a 6.5" or 7.5" ring gear configuration.. It’s been quite interesting for me to read over these old updates, and in hindsight, I was so unbelievably optimistic about getting the car on the road quickly and how, at every step of the way, I was convinced that we were “close”!. DISCLAIMER. The Galaxie 500 Site and its owner are not liable or responsible for any responses to questions that are not correct and slanderous..