I was at a car show a couple of years ago and admiring a brand new restoration of my buddies 1971 Trans Am (455 four speed). I also reviewed his restoration photo album. While looking at the carb photos I caught a glimpse of gold
(the carb was upside down) on the "bridge" between the primary throddle plates. I knew exactly what it was. He (or
his carb rebuilder) had not only installed replacement bushings on the outside of the throddle plates, the center support
was overbored and bushed as well. The 1971 455 HO four speed carb (single booster ring) has to be the most rare and valuable q-jet to aquire. And this was his cars original unit. I would never have attempted this on that carb. You have to bore into and through the primary bores to get to the "bridge. And like Cliff says, this "repair" is unnecessary. I questioned him closely on the performance aspects of his engine and carb. He said it runs flawlessly. It starts right up, comes off choke smoothly after warmup and drives like a virtual brand new 1971 Trans Am. It seems to me that by making the throddle shaft hole bigger in the primary bores, this would lead to more air getting by the primary throddle plates and could very well alter the flow charistics. What does everyone think?
