Hey guys, new subscriber here. I just bought a 1985 Mustang GT and I am having issues with it passing smog. The car is failing on HC ppm and CO% at 15mph and 25mph. Here are the readings

Reading Limit
HC ppm 425 97 at 15mph
CO% 7.56 .59

HC ppm 432 79 at 25mph
CO% 8.04 .45

I took the 4180c carb apart and the main jets are stamped 279 and the power valve has F2 and 10 stamped on it. Are those the factory size parts? If they are, what other reasons may cause the carb to run rich. As far as I know all the vacuum hoses and egr stuff is on and plugged in. I am running the cats off of my 88 on this car. Any help would be appreciated.