^^^This.^^^

Most carbs run best in the 3-5 lbs. fuel pressure range. If you run much over that you run the risk of unseating the needle and flooding the engine. My guess is that you're running right on the ragged edge, and when you brake the combination of sudden engine deceleration (read: non fuel consumption out of the float bowl) and fuel slosh causing the float to ride an artificially reduced fuel level is allowing just that tiny bit too much fuel past the needle and flooding the engine.

Set your FPR to about 3.5-4 lbs and see what happens.

 

hmm........ ill try this. tried everything else at this point but this does make sense.

i figured since holley recommends 6-7 psi i was still under sometimes.