tuning help

69 bee 383 4bbl. The engine runs rich at idle to the point your eyes hurt if you stand behind it. Idle timing set about 8 before, rpm about 800 rpm vacuum is 5 inch.
I cup my hand over the carb the idle goes up and vacuum goes up. That tells me vacuum leak. I sprayed brake clean at base of carb little change in rpm. Spray aroud intake gasket at heat cross over big change. I look online and saw valley pan with and with out fiber gasket. I did not put fiber gasket on. Do I need fiber gasket?

aftermarket aluminum or factory iron intake?

Factory iron, AVS carb

Double the initial to 16, reset carb and see if the idle cleans up. If ti starts OK leave it there.

Then fix the distributor so the total is not out of bounds.

Camshaft? Sounds like a purple 508-509ish. If so, no way that will run well the way it's set up now.

Sounds like the throttle blades are open a bunch, activating the main circuit.

I would bump up your initial, check the float settings,floats not waterlogged fuel psi at idle but you do have a vac leak which needs to be addressed first. A guy on here "roadhazard" sells thin .015" paper side gaskets for the BB valley pan. I'd get a set & glue em on your current valley pan with Permatex 99MA "high tack" the thin red spray gasket adhesive in the purple can as it goes on light seals well and is extremely tacky. Holler how it turns out. Felpro has thicker side gaskets & it all depends on the height of the manifold in the "V". Mockup dry & go from there. You want the set of gaskets (thickness) that will give you the best intake to head bolt hole/port alignment & with deck height/milling/gasket/variables it could be anywhere and you might want to use no paper gaskets & in that case I'd use a THIN/EVEN swath of Permatex #2 in the toothpaste like tube around each of the 8 port holes in the metal valley pan gasket on the "bead" on both sides. EDIT Also check needle/seat(s) condition and floats/linkage not hanging up in their travel range