Hmmm, now that I have my MAF in my hand, I took the time to accurately measure it. First off, I thought they were 70mm...mine is easily 72mm at the narrowest point near the mixing tube. The measurement was made with a digital caliper using a sturdy paperboard template that was cut to sit down past the convergent point and taped together to produce a slight drag as it is inserted and removed from the bore. The measurement was actually more than 72mm, something like 72.23mm. What's up wit dat...do they subtract the mixing tube dimensions to achieve 70mm? Am I doing something wrong?
