4160 Holley help
Make sure the surfaces on the main body are true with a ferrier's file. Modify the base plate for a check ball in the power valve vacuum port if it does not have one. To increase secondary response you can plug the vacuum balance port to the secondary diaphragm feed. It is a tiny hole located in the passenger side secondary venturi. Silicone or epoxy works fine. I also do not use a check ball in the secondary diaphragm housing and use that ball for the power valve port conversion.
Make sure the surfaces on the main body are true with a ferrier's file. Modify the base plate for a check ball in the power valve vacuum port if it does not have one. To increase secondary response you can plug the vacuum balance port to the secondary diaphragm feed. It is a tiny hole located in the passenger side secondary venturi. Silicone or epoxy works fine. I also do not use a check ball in the secondary diaphragm housing and use that ball for the power valve port conversion.