Rochester Quadrajet ID issue
 

Hey guys ... my carb is spewing gas all over the place so I have decided to rebuild the ol' quadrajet.

I grabbed the stamp and then went online to ID my specific carb but something has confused me.

Stamp says:

7046216 YD

I understand:

70= Rochester
46= ???
2= 49 state emission
1= chevy
6= auto tranny
YD= ??

The questions:

Everywhere I check 46 is not an option, it SHOULD stand for 1976, however this engine (and I assume carb) is off of a 1980 chevy pickup (PO swapped the ol inline 6 for the 350/350). Furthermore it seems that rochester went to the 170 prefix in '76 and I don't have a 170 prefix. Is this something anyone else has run into?

What is the YD?

Any help from the all knowing would be greatly appreciated!

Czar Out!

Re: Rochester Quadrajet ID issue
 

Check the casting again? Got any pics of the carb?

Re: Rochester Quadrajet ID issue
 

I guess I need to go back over to the barn and recheck that casting number - it just doesn't make sense. :)

Pictures:
http://picasaweb.google.com/tuszynsk...at88b9p7DFtgE#

Re: Rochester Quadrajet ID issue
 

Just for fun, I'm going to say it's a 1971.

The choke is pre-74, and the idle mixture screws would have been plugged from the factory if it was 72 or newer. Not to say that someone couldn't have changed that...

I also think the vent on the front of the carb was different in years 1970 and older.

Re: Rochester Quadrajet ID issue
 

Re: Rochester Quadrajet ID issue
 

The last two characters on my Q-Jet carb stamp is IU (likely in the same place as your YD) and in the carb section of my build sheet is IU, therefore I assume this was the code used at the factory. I have never seen a breakdown of this 2-letter code.

Re: Rochester Quadrajet ID issue
 

mine is a IU as well. anyone know?