3" or 3.5" MAFS

[nolimits]

This is going to sound really obvious, but is the 3" GM MAS actually 3" outside diameter?? I would assume so, but after getting one by auction it's actually 3.5". I know there's also a 3.5" MAS, so is this what I actually have...or is it an inside diameter measurement (which would make the 3.5" GM MAS somewhere around 4" OD)? The ramchargers MAFT has a setting for 1 or the other and I want to make sure it's set correctly.

 

[kpt4321]

The 3" MAF is actually something like a 3.25" outside diameter.

 

[nolimits]

The one I have is 3.5" OD, and the ID of the sensor itself (end caps removed) is 3.25". The part# on the bottom of the sensor is 89872145350. The auction I got it from said it was a 3" MAS from an Impala. Can anyone verify this? Do all F & Y bodied LS1's have the 3.5"? (if so I could check the one on a friends corvette or T/A, but they are both pretty anal about thier cars and won't be happy about me pulling out the MAS to look at it).

 

[nolimits]

Can anyone measure thiers or have an answer??