GM cars and trucks came with Quadrajet carburetors for decades, and they came on every GM makes engines at some point or another. They were considered to be a performance 4-barrel carburetor that also gave good economy thanks to the very small primary throttle bores. They fall into the “Spread Bore” category because the primary and secondary bores are different sizes. In fact, the secondary throttle bores are HUGE in comparison and way bigger than they bores on a “Square Bore” like a Holley. With this said, the square bore carburetors like a Holley or Quick Fuel have always been considered to be the best performance carburetor platform and that’s why a square bore Holley came on GM’s highest horsepower engine combos.
One thing to note though is that a well done Quadrajet can support big power and they are very well known in the Stock and Super Stock drag racing world where they regularly support power numbers that get cars into the 8’s.
In this video, Richard Holdener is going to be testing one out against a couple of others in his Other Guys series where the Pontiac 400 is going to be the test engine. Check out his details below and see what you can learn.
IS THE Q-JET THE WORLD’S BEST CARBURETOR? HOW WELL DOES THE Q-JET CARB WORK? SHOULD I UPGRADE THE CARB ON MY PONTIAC 400? HOW WELL DOES A 2G, 2-BARREL CARB WORK? Q-JET VS 4150, WHO WINS? HOW MUCH POWER DOES THE (OTHER GUYS) PONTIAC 400 MAKE? DOES A 2-BARREL CARB GET BETTER FUEL MILEAGE? WHICH CARB IS BEST FOR MPG? CHECK OUT THIS TEST ON A MILD (NEAR STOCK) 400 PONTIAC COMPARING THE STOCK 2-BARREL INTAKE AND 2G CARB TO THE STOCK Q-JET CARB AND INTAKE. I ALSO COMPARED THE Q-JET TO A 750 QUICK FUEL CARB USING A 4150-TO-Q-JET ADAPTER. IF YOU ARE A Q-JET FAN, YOU WILL LIKE THIS ONE!