[illflem]

Found testing that someone had done.
Decide for yourself.
Coolest intake temps (dark blue) are from a mod described here http://www.cumminsforum.com/forum/general-diesel-discussion/127696-modify-stock-airbox.html

from http://www.psmdiesel.com/prod.php

 

[illflem]

which one is the BHAF on this?

Red line on the top.

It may be cooler air but will it flow as much air as some of the aftermarket intake systems.

You are 100% correct but how many folks here are putting out enough hp where they even come close to maxing out the flow of a stock airbox style filter?

 

[illflem]

Where are you measuring this?

Think he meant EGTs.
Your 20° number is right on, the intercooler does an excellent job but the airbox mod lowered my egts about 100° also.
Probably because of denser air.