txdxrider wrote:
Ok..... So weight full of fuel with passengers - 6625
Front axle - 3375....sticker is 3600
Rear axle - 3250.....sticker is 4200
GVWR of 7400 so good up to circa 700 hitch weight
Stock I am GCWR of 11,500
So 4875 left over....
Once I do the mods for the hd towing - GCWR of 14,000
So good around 6500 pounds TW
If you look at a trailer that is 4500 lbs fully loaded (not dry), you can expect an average of 13% of that to be tongue weight that is carried by the truck. So 4500 x .13 = 585 lbs tongue weight. Subtract that from the 7400-6625=775 that you have available for cargo and you are right there. That leaves 775-585=190 lbs for stuff in the back of the burb.
A 4500 lb trailer added to the burb at 7400 gives you GCWR of 7400+4500=12,000 lbs, within your new "post-mod" number.
So you are really looking at trailer with dry weights in the 3500 lb range, which I think may a little on the small side to full time with a large family. Suburbans are very capable tow vehicles, but as with any SUV, you can tow a lot or you haul a lot, but not both at the same time. We found that the 1200 lb TW of our trailer ate considerably into the 8600 lb GVWR, and with 3 kids (our 2 and a friend) the scale told us were at 8600 lbs.
You will find that modding the truck is a slippery slope, as it will never be "quite" up to the task...been there, done that, spent the $$ and got the T-shirt!
I would suggest that you reverse this process and first select the trailer that you think will serve you well as a full timing family. Then get what you need to pull it, likely a 3500 series van with either a big block or a diesel.
Your numbers and thought process are right on, I just think you are running out of lipstick to put on this pig....