Rochester Quadrajet Carburetor Notes: 

• The thinner the secondary rod, the more fuel will flow into the secondaries. 
• A letter stamped into the hangar assembly can identify hangars.
• The lower the letter, the higher the hangar holds the rods, which will give you more fuel sooner.
• Replacement hangars and rods are available through your GM dealer, Edelbrock, junkyards and many other online resources.