Quadrajet Madness IR intake and 4 carburetor test driving and tuning
First series of test drives with the 4 carburetor setup. Many things learned from this experience!
See 1976 Chevrolet pickup with Rochester quadrajet upgrade on SBC 350 V8. We removed the hood, mounted a camera looking down on the air horn, and took it for a spin, running wide open on an uphill grade. See how the secondary air valve responds to rpm drop at each upshift of the THM. Also included is a smoking burnout.
750 vs. 800cfm Rochester Quadrajets-how to tell them apart
There exists a ton of misinformation regarding the actual airflow capacity of the Rochester Quadrajet. Not many people know how many variations there are or how to tell them apart. Here is a simple video explaining how to identify each size based on casting design. I will cover the "cfm-limited" carbs in a separate video.
The Quadrajet to Edelbrock carburetor swap - step by step
Replacing my old Rochester Quadrajet with an Edelbrock 1406 carburetor. This is a 1984 Chevy K20 3/4, just a yard truck for plowing my property. The old Quadrajet got gunked up from a broken fuel filter so I decided to try swapping on this old Edelbrock. I had pulled this Edelbrock off an El Camino with a 305 I had about 10 years ago and it has been sitting since. I popped the top and cleaned the inside, also flushed the passages with carb cleaner. Seems to run well. The Edelbrock 4bbl is not a direct bolt on to the stock intake manifold. It has a slightly wider bolt pattern and the shape of the openings is different. To facilitate installation I bought the Edelbrock adapter kit model 2696 which was less than $30. It includes the adapter plate, two gaskets, and mounting hardware. I also purchased for about $8 the Edelbrock 8009 throttle cable adapter kit which allows the stock GM throttle cable to interface easily to the Edelbrock caburator armature. The biggest adaption here was the fuel line. The Rochester Quadrajet has the fuel filter in the the front of the carburetor and is fed by a metal fuel line that threads in there. The Edelbrock's fuel inlet accepts a rubber line and is on the side towards the rear. I cut my metal fuel line and attached a rubber line to it with an inline fuel filter to the Edelbrock 1406. This seemed to work very well. I had to extend my PCV hose about an inch. This was easily done by cutting it and splicing with a piece of metal tubing. The brake Booster vacuum line on the rear of both carbs is identical and required no modification. Same with the distributor vacuum advance, same location on both carburetors. Parts Used: Edelbrock 2696 adapter plate kit Edelbrock 8009 throttle cable adapter Rubber fuel line Inline fuel filter Hose clamps Tools: Flat head screwdriver Phillips screw driver 5/8" tubing wrench (fuel line and brake Booster fitting) 1/2" wrench (carb mounting bolts) 3/4" wrench to swap brake Booster fitting Something to cut fuel lines with