By adding the IFR (if your installing them into the air bleeds and not the idle fuel feed channels)you are enrichening the mixture, remove them and shoot for 14.5+ AFR at high idle above 1500 RPM, use the secondary throttle blades also to get the RPM you want, not just the primary throttle blades
I drill and tap both the idle fuel feed channels and the power valve fuel feed channels to #6x32 and use blank allen headed brass set screws that I drill out to the size I want to fine tune the AFR at idle and at slight power valve opening and then tune the high speed air bleeds sizes for the WOT AFR tuning
What year is your Dodge Pickup, 1954,55,56 or what year?
I had a 1955 D500 flatbed that I converted into a car hauler and sold it to a friend and later buying a 1957 D300 whup car hauler that I ended up replacing the entire cab with fenders from a 1960 pickup, motor and a D60HD rear end out of Class B motor home chassis
If your carb is a four corner idle carb try from 1/4 to 1 full turn out from bottom on all four mixture screws and see what that gets you on the AFR, if it is primary only idle mixture blocks try from 1 to 1 1/2 turns out from bottom with the secondary throttle blades barely opened at idle
You really need to set the total timing as soon as possible, that can have a big effect on the idle quality and heating issues due to not enough advance, I shoot for 34 to 36 degrees total at or above when the mechanical advance is all in