Try richening the low end. Good rule of thumb to use to know you are in the ball park for low speed needle is the pinch test. Pinch the fuel line and engine should die in about 4 seconds while idling. Longer than that too rich, shorter too lean. This is just to get in the ball park for low needle. Sounds like the typical low end lean and high end too rich to compensate for low end being too lean. Also set idle gap with a paper clip to start. These are tricks I have been shown and have worked for me. Set you high speed needle to factory which should be close to flush. Hope this solves some of your issues. Did you get a lean bog going down the straight or gurgling bog like the car doesn't want to get out of it's own way?