'99 Ls1/'01 Ls1 Maf Queston...
from your other post, if you are going the 90/90 route you may want to consider this.
SD is another viable option.
EDIT:
Just re-read your post. If you are chaning a 75mm for a 75mm then yes, they should be interchangable. If you are upgrading from a 75mm to 85mm, then you will need to do some tuning. Tuning a MAF is not my favorite thing to do.


