Carburetor expert, I need your help!

[OregonC20]

If I wanted to replace my stock Rochester 4 barrel carburetor with another Rochester, do I need to find one with the same number as mine? my has 7040206 1S 0700 numbers on it. Or what other brand models can I use to replace the Rochester? I owned a 1970 Chevy with a 402.
Sorry, I'm not savvy when it comes to carburetors.

Thank you!

[red71c10]

You need a Q-Jet that is dialed into your specific application. One of the reasons they have such bad reps is that people tried to sell generic replacements. "Just pull it off the shelf and bolt it on" doesn't work. The carb that originally came with your truck was set-up for that type of truck with that type of engine/trans, horsepower, gear ratio etc... There are a few places on the net that will rebuild them to fit your needs. You provide the specifications of your truck and they will set it up to fit. Probably costs more than $200.00, but probably worth it IMHO.

[Bus Ted Knuckle]

The national auto parts stores all sell a re manufactured q-jet that is application specific. They vary in price, so shop around. You will be pleased with it right out of the box.

Any q-jet that is set up to the correct specs (for the carb, not the motor) will perform reasonably well on most any application. In other words, if you have a 72 model q-jet on a 69 model 350, you want to set the carb to 72 specs. The specs between q-jet numbers can vary A LOT!

What is your carb doing that you feel you need to replace it?