GCWR (Gross Combined Weight Rating) FOR '93 K1500 BURB?

Just got this:

http://www.tomstj.com/trailer%20opics%20at%20800x600%20001.jpg

to haul my ~4000LBS TJ with a 93 K1500 5.7L.

I'm at work and tryin to figure some things.
Need to know if my guess-tamites are close on GCWR & GVWR

TIA, Tom

you should only tow 6,000 to 6,500 pounds including the trailer. I think a 3/4 ton is only rated to tow 8,500