hey guys i just wanted to know if any of you have tried the carburetor substack assemblies that bolt onto the carburetor, increasing the air horn surface area. theyre made by k&n and are supposed to increas gas mileage and power but i put one on my 460 big block with an edelbrock carb and it gave me a hiway speed 1/2-3/4 throttle stumble, and the secondaries didn't want to work correctly. I took it out and the truck runs great. if its increasing airflow, should i be increasing the air/fuel mixture?

 

Originally designed by Holley in the lates 60/early 70's, they do work but with carb'd engines you did have to adjust the fuel mixture a tad with the mixture screws.

 

ok i'll try to mess with the a/f ratio. I think if i fatten it up a bit it might get rid of the stumble. Also i installed a Mr. Gasket adjustable inline fuel pressure regulator and i love it! The motor feels stronger at full throttle.