Holley 600 dp jet help

I would disconnect the secondary linkage and tune the primary first. Get the engine throttle response nice and crisp on the primary first, then tune the secondary. My guess is you are too rich on the primary also. Start with a 64 up front and see how it runs. Check pump shot also. As soon as you add throttle the primary shot should occur. Secondary shot as soon as the rear butterflies move. I assume you have the idle mixture, float level and timing curve correct already.