Holley 20-13 Secondary Diaphragm Spring 🔧 Kit: Maximum Performance Upgrade for Reliable Engine Efficiency Review

Holley used to paint the entire spring the color it should have been (a long time ago), now just a bit up where it is wears off with normal use so they all mix. A lot of money for a pair of feathers but I needed a set.

These springs are good for the job. I went my way from the lightest to the one that worked for my application and they seemed properly positioned and well constructed. The colors were easier to read than I thought.

I bought the whole set for one white spring (the lightest) and got a second simple spring instead. an extra spring that I never want to use. This is why I gave 1 star and will not change it until I get what I paid for. How do I get the ones I need?

Not available in retail packaging. The connection to the included spring is non-holly and provides reverse rev range opening and full opening. Does not include Holley instructions. I don't think this is a real Holly set. All the characters look like it's a fake packaged and sold as a holly. The feathers themselves look good. Time will tell if the quality is right.

This is definitely not a Holley product. I have some more Holley springs to compare and there is a difference. The coils don't match, but that doesn't mean the spring rate isn't the same, the two uncompressed springs seemed to have the same spring rate when compressed, but that just feels. I love that some of them are fully painted instead of just on top like the original Holley springs. The colors seem to be quite distinct.

I should have read the reviews before buying. As it was marked as a Holley product and the part number was used I figured it would be from Holley. It is not. You will receive sprayed feathers in a heat sealed bag with a poorly cut copy of the feather size chart. I have tested my vacuum diaphragm with a bolt on the actuator rod with these springs and have had great results with the original Holley kit I ordered from Summit Racing. Holley springs are painted on the top only and come in a variety…