Reuben -

The use of a rising rate regulator can compensate and provide needed fuel, provided it is properly tuned. From what I've read (not really experienced), these early MAFs don't have much influence on mixture except at/near idle.... I think they mostly tell the ECU that the engine has little-to-no load. As the engine draws more air, I think the MAF output signal decreases - or is ignored by the ECU with increased rpms.... whether these MAFs have more influence on fuel mixture or ignition timing, I don't know.

I'd think that the 3.5L MAF might be ok on a 3.0L so long as the signal voltage is the same at 3.0L and/or 3.5L idle - and the curve is linear as compared to the 3.0L MAF. If the 3.5L MAF reads the smaller air flow of a 3.0L at low speed operation, it could be harmful to a 3.0L and cause a lean idle - but that could be corrected with the regulator by raising the base fuel rail pressure to compensate with more fuel - or with larger injectors at the same pressure.

I suspect there could be a benefit of less air flow restriction, but I want to stay as close to stock initially and make incremental changes to see what happens.

Frank