^^^ that is what I have read as well. And owning a 3800 and seeing the MAF, it is the same inside diameter as the throttle body, so getting a larger one will not do you any good.

If you have TBW then your MAF is part of the throttle body and you are kinda stuck with it. Most 98's were cable controlled anyway so chances are you have the removable MAF.

Massey

 

Yup a large MAF will just bottleneck if the TB is smaller. However removing the screen from the MAF will help a bit.