real world weights

any body know the real world weight of a 2007 lance 1191.i have a 2013 lance 1050s on an 03 f350 drw and am considering trading for a 2007 1191 but lance shows about a 900lb weight difference.i had a 2005 1191 on a chev .drw and recall a gvw of under 12000 lbs.my f350 is about 400 lbs over gvwr and would not like to go down the road 1500 lbs over but i wonder if the 1191 is really that much heavier.