Ok just bought a new TV 02 excursion with 7.3 powerstroke 4x4 it has about a 6 inch lift on it, and they used blocks in the back. We have a 30 ft. TT we pull. Can we tow with those 6 inch lift blocks?...
Without pandering to the off topic admonishing the op for having a bad arse lifted rig, yes it will probably tow fine. But spacer block lifts unless coupled with traction bars to reduce axle wrap will try to twist up more under power compared to bars or a spring lift.
Unless your flogging it off the line or in sand/mud, it'll be ok, just know that's kind of a weak link and is a little more show than go.