One thing to keep in mind when lowering the fuel level on a holley. Once you have turned the adjusting nut on the top of the needle/seat down (you will get a burst of gas due to the fuel pump pressure) bear in mind that the fuel in the bowl hasn't been used for you to gain an accurate reading. I put a rag on the intake manifold just below the front bowl. Then i loosen one of the bowl screws to drain some of the fuel. This allows the fuel pump to raise the fuel level to the new setting that you just adjusted the needle/seat to. If you merely screw the adjustment down, you wont lower the level until you actually take the car for a ride.Draining the bowl slightly simulates this. The same applies to the secondaries. Unless you take the car out and tip the secondaries open the fuel in the rear wont get used and adjust to the new level. An ideal float adjustment for me is to have gas slightly wet the threads on the sight plug hold when the car is given a slight nudge. Having it trickle out seems to be a bit much as the fuel level will no doubt rise when heated.
Furthermore, i agree with the gentleman above concerning spacers. Holleys tend to run better when they are cool. My 429 f150 experienced some fuel percolation especially after shutting a hot engine off. The rapid heat tends to raise the fuel level causing it to percolate and spill over into the primary throttle bores. Going to a teflon type of spacer cured that for me.
Hope this helps in some way. John
Furthermore, i agree with the gentleman above concerning spacers. Holleys tend to run better when they are cool. My 429 f150 experienced some fuel percolation especially after shutting a hot engine off. The rapid heat tends to raise the fuel level causing it to percolate and spill over into the primary throttle bores. Going to a teflon type of spacer cured that for me.
Hope this helps in some way. John
