I am in the process of taking the original 400 engine out of my 68 convt to rebuild. I checked the engine block and the codes match and the vin number matches down next to the timing chain cover but my Rotchester carb has a code of 7029270 which according to the info on this site, means that the carb is from a 1969 Ram air IV automatic 400 Firebird. Are these codes absolutly right on this site? My car was manufactured at the end of 1968 in November of 1968. Did they switch carbs at this point by any chance as I wouldn't think they would have made many ram air IV carbs otherwise with that code?