I have the 4500s and I took advantage of the Osh deal Navworx had on their new certified WAAS/ADS-B box.

I also bought the ARINC option, shouldn't it allow me to interconnect everything through the EFIS using the Navworx unit?

Everything = TruTrak DII VSGV, GTX-327, SL-40, GNC-250XL, PMA-4000 Audio Panel

Glenn Wilkinson