Am getting ready to pick up my 2003 335/RLBS with Hensley hitch.
After reading some items about big trailers with hensley hitch puting a twisting motion on the stock reciever on the round tube GM hitch at the trailerlife.com forum at
http://www.trailerlife.com/cforum/in...id/7350273.cfm
look at the pictures around page five to seven on this thread.
I decided to replace my factory hitch with a Reese class V that has 2 1/2 inch instead of two inch reciever.
Note the square tube gm hitch if fine.
I believe the round tube GM hitch if fine with a normal trialer
but apperantly the combination of the round tube hitch and the extra forces generated by the hensly keeping the trailer from swaying can "under certian conditions" cause hitch failure.
Just a heads up for anyone else towing a big trialer with the GMC round tube hitch.