From my limited knowledge, 1500 HDs came with the 8 lug axles and wheels found on 2500 and 3500 models. They are NOT a regular 1500 Chevy or even the W/T models that come with 6 lug axles and wheels. For a 7,000 lb TT it should be more than adequate to tow cross country. To be sure, they can look at the numbers for their particular truck. What axle ratio do you have and cab/bed configuration? Here are Crew Cab numbers found on another site.
2003 1500 CC 6.0L V-8 Towing capacity 8,200 lbs w/3.73
2003 1500 CC 6.0L V-8 Towing capacity 10,200 lbs w/4.10
"The 1500HD has 8 lug wheels and a 9.75 semi-floating rear axle, along with the 4L80E transmission used in the 2500HD. With a 6000 GAWR it's way above other "1/2 tons". In fact the 1500HD is nearly identical to the pre-2000 2500 series trucks."
Bob and sometimes - Nina - a Staffordshire Terrier/a SPOILED pit and her kitty Spaz
2006 Dodge SLT 2500 4x4 Cummins Quad Cab w/AT and 3.73
2007 Salem Sport LE 26FBSRV (TH) w/ my Victory Motorcycle in it or a EZ GO Shuttle cart.