I have a 1990 GMC Suburban 2500 with a 454 engine. I called a local RV dealer and they put it at btwn 8500-10500 pounds. What would the difference be, and how could I find out? The trailer I'm pulling is a toy hauler which weighs 7300lbs empty, but with full tanks and a couple of ATVs and other gear I'm sure I'm looking at an extra1500-2000lbs. Also, what are the consequences of exceeding my tow rating? Thanks.