My 1973 numbers matching U code 455/TH400 Cutlass has a carb code that ends in an odd number indicating the carb is for a manual transmission. The carb number is 7043251. The date code of the carb makes sense for the build date of the engine and car. The car only has 94,000 miles and would seem unlikely someone changed carbs. Has anyone seen this before? Maybe the odd vs even numbers didn't have as much meaning by 1973?

 

Doesn't always mean it's for an auto or manual. Note, the 69 H/O has a 7029251 carb and they're automatics. I believe your automatic carb number is correct, and the manual transmission carb number for the 73 442 w/455 was 7043253.

It also appears your current carb was manufactured in the first couple of days into April. 093rd day of 1973.

 

That's great, thanks! The engine block also has 93 cast in it by the distributor and the car was built in early May which makes sense.

 

This myth will never die. Every single 1969 Hurst/Olds came from the factory with a TH400 and a 7029251 carb. Every single 1970 W30 with MT came with a 7040256 carb. Nearly every Olds full size built in the late 60s and early 70s with a 455 came with a '251 carb and a TH400.

Believe factory literature, not some third-party book or worse, the interwebs.