There is the possibility of switching from VAM to MAF, which involves finding the proper resistance MAF sensor, and then the pipe to fit it in. It would offer better airflow, and would be more than a match for a "better" VAM/VAF. It would take some time and thought, but I know it's possible as it's just a resistor. The VAM is a mechanical potentiometer with the air flapper moving the pot's wiper....simple stuff. The MAF is just a thermistor that's cooled by air...technically more reliable if it doesn't get gunked up, and also faster acting, with far less restriction. Maybe see if a 2nd gen, or 3rd gen SPI MAF works out..chances are those would be pretty direct fit with the proper resistance.