Also, be careful about buying a WDH c/w spring bars unless you are confident you know what the tongue weight is likely to be. You mention a 650 lb tongue wt. but the dry tongue weight will definitely go up and you don't want to end up with a set of under-sized bars. Over-sized is not good either. You'd be safer basing it on 12-13% of the GVWR rating which is typical for when you're are fully loaded up for camping. Your tongue wt. could possibly be over 1,000 lbs. In some cases the tongue weight can be closer to 15% of the GVWR. I would weigh your TT once it's loaded for camping. Is the dealer sizing the spring bars? What if they end up being too small? Dealers are notorious for messing up WDH installations. I would check it over at home - torque on bolts, bar angle, chain links and amount of wt. transfer. Which brand and type of WDH?