ive heard from multiple sources that the intake and exhaust camshafts for the 4AG 16v are universal and can be interchanged. is this true?

I believe that they are on the TVIS engines, so you could run two exhaust cams if you
were short of an intake cam. The knock pin may be in the wrong place to use the back
plate timing marks for the intake side, so you might have to set the intake side cam
using a timing wheel and dial indicator.

Cheers... jondee86

The Exhaust cam is interchangeable for either in or ex, but the intake can't be used on the exhaust since the distributor gear isn't cut on the intake cam. If you are going with a crank sensor that last bit goes out the door.
The knock pins are the same, sprockets have two holes or notches for either intake or exhaust. Aftermarket adjustible sprockets are typically keyed for intake or exhaust.

If you're looking for a different spec cam for the intake, the exhaust and intake are the same in the engines generation. Early gen has 4 degrees more timing and a modicum more lift than the late. Check out the cam story or history. It's somewhere in this site. Look in the archived section.

Look for the "4age camsahft comparison chart". Might have to go through your search engine instead of using the club4ag search bar.

More info than you were looking for.