1987 318 Tuning with Summit Carb

Something very odd about this carb. Post #67, idle tubes measure 0.053" ??? Surprised more folks have not commented on it. Or, is the restriction in the top of that thin tube? Check with drill bits or thin wire if drill bits are not long enough.
A general purpose over the counter 600 cfm carb, no matter what brand, you would expect to see an idle jet in the 0.028-0.035" range. Using 033 as datum, 053 represents a 158% increase in area, more than 1.5 times. Something is not right.

The idle jets in the spec sheet showing as 0.046". I wondered why that size would be given because they are not replaceable; the idle feed is the brass tube, but the restriction may be at the top of the tube, as discussed.

I believe the 046 refers to the Economizer jets & I believe they are two replaceable jets shown in the red circles. They are also part of the idle cct. Econo jets are always above the fuel level, as these are. The Econ jet in the 6000 series TQs are in the 046-048 range & also in some AFB carbs. The econ jet supplies mixed air + fuel to the t slot & idle mixture screw port, for idle & low speed cruise. It is a jet that might need to be changed so it's position in the cluster makes sense [ to me ].

Pic in post #53 of the booster assy. I see holes in the casting that are probably air bleeds. Not sure about the brass jets.