The 1975 Olds q-jet is a completely different design, so you can't compare the jet/rod set-up to the 1979 model, it just doesn't apply. They used a front located APT system, and most had a secondary power valve and single jet/rod to add additional fuel. I avoid those carbs here if at all possible, they were only used in 1975 and early 1976 until they figured out a much better way to control part throttle A/F using tapered metering rods and an APT adjustment screw.
The 1979 carburetor uses tapered metering rods, most had "K" series rods in them, which provide very little control of part throttle A/F using the APT system. They could be "P" series rods, which would provide more adjustment as they taper .010" on the upper section vs .005" for the "K" rods.
It's also likely that the primary power piston arms are bent anyhow, and they MUST be exactly even on those units for the APT system to work correctly. Nearly 100 percent of the "rebuilt" carbs I get in here that don't work correct, woln't lean up and will not get thru emissions have bent arms for the primary metering rods.
There are other things that effect fuel delivery to the engine not related to jets and metering rods. Float height, fuel pressure, and the size of the fuel inlet seat are big players here. I'll bet the carb was "kitted" with the wrong size fuel inlet seat, and the float height may not be correct as well, which throws things off some.......Cliff
