Cliff's Quadrajet Parts and Rebuild Kits

I think the LIAB could definitely be part of the problem with the other carb.  I've found that 0.062 vs 0.078 just seems to work better for off-idle.  As for metering area... I don't think you can compare SMAB carbs with DMAB, as they seem to behave different with regards to main system metering area.

  Novadude,
 The last carb was a SMAB, #17084226, and it had a larger metering area than this one does.

  I'll start with adjusting the APT, and if it doesn't work I'll make the LIAB's on this 17080213 replaceable with set screws, and try smaller ones until it gets into an acceptable AFR range. Hopefully it doesn't change anything else. The higher RPM mixture can be fixed with the jet/rod combo and the APT setting.

 The difference between these two is definitely confusing, but I'm gonna figure it out, it might take me a while, but I'll get there, (most likely with help from you guys).

Have you tried adjusting the APT on this carb? How's heavy part throttle?

 No, not yet, it was just getting dark when I got back from the test drive.  I do need to look at that, I didn't think about it being set too high.  I set it at 3 3/4 turns according to the specs I got from Kenth. I thought it was a bit much right off the bat, I don't usually run it up until I try it set at minimum first. But since I was trying to set this one up exactly like it left the factory I figured I'd try it and see how it works.
 I'll give that a try before I do anything else.
 But if this doesn't change it, would the LIAB's be a possible cause?

 The heavy part throttle is rich as well. I don't remember the reading, I forgot to bring my recorder for notes this time. But it's definitely fat from top to bottom.
 Im actually glad too, I was beginning to think I had some other problems with the engine instead of the carburetion. This just proved it.
 Thanks for the suggestion.

  Well, this carburetor runs rich from off-idle to 3500 rpm. It's not the timing.
  I noticed that this one has a  .016" smaller LIAB than the other 3 previous carbs, so is this the whole problem with the other 3, the LIAB's were just too big?

 And how would I get this one to lean out a bit in the off-idle to 1500rpm range? Enlarge the LIAB'S slightly?

 Something else I noticed is that the jet/rod combination in this 17080213 carb, (#72/49M), has a cruise metering area of 2.19 thousands of a square inch, yet runs much richer than two of the other carburetors that have a jet/rod, (#72/44 from Cliff), metering area of 2.55 thousands of a square inch, and the 3rd one has a metering area of 2.52 thousands of a square inch, (#70/41K). What's up with that?
 Does the LIAB's have that much effect on the AFR?

Based on Kenth's info, it looks like the 17082213 and 17080213 are pretty close.  What I have listed as POE for my 17080213 are the discharge holes above flaps.  For some reason, I did not document the well re-fill holes.

This is what i have on the 1980 350 HD Truck 17080213 Rochester and Carter units.

  That's very very helpful, thank you Kenth. So it appears that the base plate has been switched, but with this information I should be able to set it up correctly. I've already drilled the mixture discharge ports to  .108, and the bypass air is not hard to change.
 Your list explains the differences between what MCX and Novadude have provided and what I've measured. This looks like a combination of both Rochester and Carter. I wonder if it's a high altitude calibration.
  My thanks to MCX, Novadude and Kenth for your help with this, it's much appreciated.