Of the hundred carbs I have done, out was richer and in was leaner. To get a turn difference there has to be something different between the two idle circuits. Damaged needle valve or seat or blocked idle venting port. All later carbs are designed to drop the idle circuit out as venturi speed goes up. They did it with air bleeds which by design are very small.With all due respect, Bob, with every other carb I've ever messed with in over 35 years of cussing at and hammering on older Mopars,(2 and 4bbl models), "In" is rich, "Out" is lean. You're turning it out (counter-clockwise) to allow more air (not fuel, hence the reason it's actually the Idle Air Circuit we're talking about) in. The idea is to keep the curb idle speed screw barely turned in, so the carb is drawing air and fuel only through the idle circuit. By turning the idle mixture screws in, you reduce the amount of idle air, requiring more idle speed screw adjustment, opening the primary throttle plates, negating the idle circuit (and ported vacuum draw) which then requires more fuel. The FSM would obviously be the place to confirm the direction, if anyone has that.
Thinking back, I actually had this same set-up on my very first car, a '77 Fury with the E57 360 2bbl, but I can't recall anymore which way the mixture screws went. It's possible that particular carb is arsebackwards, where "in" would be lean, but I wouldn't bet a penny on that.
One last note to the OP - check your base timing, and also double-check your crank dampner. Agreed on keeping it stock. Yes, even an NOS ebay carb would need a gasket kit with Viton seals for today's fuel. There is a boneyard near me (western WI) that is a no-crush yard, but I think if you replaced the choke pull-off (vacuum kick), you should be in pretty good shape. The 360 is a bit more tolerant of carb issues than the 318. The 318 will run beautifully with just the right mixture and timing. The 360 seems to be less fussy. Just my experience.