Around five years ago I bought a 56 olds 88 324cid. The guy I bought it from replaced this Rochester 4 Jet carb with an Edelbrock.
I can’t find any numbers on it, only “pat applied for”. Any ideas on where/how to find the date of manufacture?

Thanks

 

If I'm not mistaken, the carb number could be in the location circled. With a little imagination, it looks like there might have been some letters or numbers there that have worn off or have been obscured by dirt. You might try cleaning that area gently and perhaps do a pencil rubbing to bring up the numbers.








Not sure if this is of any help, but the carb number on the quadrajet on my '78 Toro is oriented vertically on the driver's side of the carb in the location circled below. That's why I suggested what I did above as that's also a vertical location.

 

Thanks Jaunty, I’ll take a look see.

 

THe OP's carb is NOT a Quadrajet. It's a 4GC, sometimes called a Quad-Jet (without the "ra"). The carb number was on a sheet metal tag held under one of the air horn screws. These frequently got "lost" at the first rebuild. Note the triangular tag in the lower RH corner.

 

Thanks for the info, Joe, I was able to determine that the one I have is a Rochester 4GC #7007221, 1954-56 Oldsmobile (7221 was stamped close to where the triangular tag should be).

 

7007221 was the 4GC used in 1956 on the automatic transmission Oldsmobiles. It had the auxiliary throttle valve assembly on the secondaries. The 1954 & 1955 4GCs did not have this and had different model numbers. Unfortunately, the month/year date of manufacture went away with the tag.