John, I’m doing this on my RV7. The Echo/Skyfyx provides ADSB to my 740 by WiFi and the 740 provides USB NMEA data to the TruTrak and my Dynon D100 EFIS. The 740 & 740b are reported to be functionally equivalent. Hope this helps. BTW my transponder is a GTX327 and the whole thing seems to work fine. Bob