We were considering the AF 990, and had a Dodge 3500 LB, SRW. By checking all the #s, and having the dealer weigh the unit because of a huge difference in the weight he was quoting, we would have been 1100 lbs over GVWR. That's including the tongue wt of a 3000 lbs boat.
That is too much wt for our comfort level. All he would have done was to add airbags. Learning so much on this forum, we would have to add about $7K in mods to the truck to make it work safely (for us). Some folks are braver and will say differently. You have to go with what will make you happy.
We love our new DRW and most importantly, we feel safe. BTW, we didn't go with the 990 because we found another TC with a nicer floor plan and more space, not because it's not a nice unit.