T and T results
Lar414 is right on track.
I would say the idle thing is either floats or you butterflies are just touching on the tranfer slots. The other thing is the 850 holley, I would ace that baby and run a 750. You'll get better velocity and throttle response from a 750. What kind of booster is in the 850? down leg? or annular. If your lift is mid 5's I would guess your duration is 240's @ 50. Are you X heads ported and if so how much? That's a lot of cam and compression for X heads unless their ported some.
What are you shift points?