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Ideal loaded tongue weight range @ 5,500lbs would be 13% to 15% = 715lbs to 825lbs.
I would go with the 1,000/10,000lb Equal-i-zer WDH...., and with proper installation/adjustment it will provide great weight distribution/sway control performance.
If you want to truly "dial-in" your WDH, a CAT scale visit under loaded TV/TT conditions will provide all the information one would need.
CAT scale how-to: http://www.jaycoowners.com/forums/f3...v-tt-3871.html