I have a 3pk and a Spectra module and they work fine with my Novak receiver. Make sure the radio is set to PPM. There are 3 settings, PCM, HRS and PPM.
I was told at the Losi race that the rear arms aren't ready quite yet for the XXX-T. Jesse Robbers (who is a super nice guy) appeared to have the new truck, but he told me most of the parts were off of the buggy. Some Losi drivers didn't even have the new tranny in their trucks.