Mike wrote:
My boat/trailer is about 4500 lbs. Not sure about transmission other
than brand new Jasper transmission about 4000 miles ago. Have
appointment to put new brakes on next week, brand new ball joints about
4-5k ago.



Ouch!

Even if your Blazer is rated for 5000 lbs...they recommend you don't tow
anymore than 80% of your capacity as a safety factor.
That would drop you down to a 4000 lb safe tow.
The question is...is your vehicle rated for 6500 lbs?
The dealer can check this out and if not... I'd keep my trips short &
sweet under the speed limit.