Difference between 00 MAF and 01 MAF??
Different calibration/tables in the computer comes to mind. They are a waste of money, keep the stocker. Farting around will only cause more problems than it helps, do a search for MAF in the external section and you will find tons of threads talking about this.
If you upgrade the whole intake system to 90mm or so, then an 85mm MAF would be a great upgrade. However, most tuners hate your guts when you bring them anything besides a GM MAF. The z06 MAF's are 85mm with no screen and work great, but they do require tuning work.
Point is, only upgrade if you're willing to have tuning work done to compensate for the change, and you actually need more flow. The stocker is easily good to 450rwhp n/a.
If you upgrade the whole intake system to 90mm or so, then an 85mm MAF would be a great upgrade. However, most tuners hate your guts when you bring them anything besides a GM MAF. The z06 MAF's are 85mm with no screen and work great, but they do require tuning work.
Point is, only upgrade if you're willing to have tuning work done to compensate for the change, and you actually need more flow. The stocker is easily good to 450rwhp n/a.
I think they are different because from 2000 to 2001 GM used a slightly different cam for emmissions in order to get rid of the EGR on the cars. I may be wrong to the reason but I KNOW thiers a different cam and a few other changes so that was probally to better fit the changes made.
