I have a 1970 GTO Judge, manual trans 400 ram air 111. The car seems to bog down at acceleration. I was planning to rebuild the carb but have an issue. The number on the carb is 7040263 with an additional number of 1075. I assume that this number is the build date of the 107th day 1975. This is where I'm confused. The 4th number in the serial number is a "0" which would mean that the carb was built in 1970 rather than 1975. This is where I'm confused. When was the carb actually manufactured? Also in looking over the shop manual I see that the carb for this car is 7040273. I would appreciate if someone could help me out with this issue. When was this carb manufactured and what is the actual carb for this car. Any help would very much be appreciated.