Inliners International Forums General Discussion Engines Holley Carb Secondary Jet Question

Seems like a really easy question, but I haven't found the answer on YouTube or online parts house. I have the Holley 4BBL 390 CFM carb.

When I pulled the bowel off the secondary sidea, I see a plate held in with a bunch of screws (Allen wrench head?). There's a 58 stamped in the plate. My guess is that's the jet size.

Where do I find the jetsigned? Is it the big plate? On the backside. My 58 is smaller than others.

Thanks!