carb tuning help

I am new to carb tuning and need some guidence. i have a proform 750 mech. secondaries carb. it is running super rich. it burns my eyes in a matter of minutes when running. I know that changing the jets to smaller ones will lean it out but what do i need to change or adjust along with them. the carb is stock out of the box.

engine specs.

383 with mildly ported 84cc eddy heads.
mech. flat tappet cam .525 lift 294 duration
110 degree lobe seperation
9.5 compression
mopar m1 single plane intake
tti 1 3/4" headers

the carb specs from the factory.

primary jets: 74
secondary jets: 84
idle air bleed: 70
high speed bleed: 33
primary nozzle: 31
secondary nozzle: 31
needle and seat: 110
power valve: 4.5

the engine runs smooth and transitions from part to full throttle smoothly. no bogs or surges. runs nice and smooth just really rich. plugs are black.

was thinking i should step down at least 3-4 jets on primary and secondarys. from the little bit that i do know and have read the 4.5 power valve is pretty close.

any input would would be awesome guys. recommendations, explanations of how thing work, etc. i ordered a holley tuning book from amazon today so that will help also.