Recently looked up my Rochester 4MV (Qjet) number: 7029207, which shows this as a 1969 350 325HP Vette carb for a manual transmission. My car is AT, would there be any performance issues with this carb being that it is made for a manual transmission? :confused: I've also read that Rochester didn't always follow the numbering convention precisely.

It would depend on if it was rebuilt with the correct CFM ratio for your automatic application? The rods and jets are calibrated for the correct mixture and are subject to factors such as transmission and emission control. If it runs well I wouldnt sweat it unless you want the correct list #. Even if you find it you need to analyze the rods and jets to be sure it wasnt adapted to another configuration. Remember that odd numbers at the end of the list are manual and even numbers are auto.

Thanks, no issues so far with it.

I don't think there's much of a difference between q-jets with auto's or manuals.

It's possible that there was a connector bolted to the throtle linkage of automatic q-jets to allow for kick-down linkage. Or perhaps since automatics idle lower in drive than a 4-speed car would in neutral, that the power piston spring is stiffer on auto cars so that it doesn't go rich at a stop light. And it's possible the that the opening of the secondary butterflies (the uppers) are delayed on automatic cars so the engine won't bog.

But all this is too minor to worry about and all can be adjusted to your engine/tranny combo.