need towing advice

I have a 1988 4x4 suburban with a fresh advance auto 350 freshly rebuilt 700r4 with a 20k tranny cooler 3.42 gears and I put 3/4 ton springs on the rear to eliminate the sag problem I am looking to tow a tractor that weighs almost 7k on my car trailer to my house and back to my friends to crop off when done it is a 1/2 ton so I am worried that this might be more weight than it wants any advice

Not that you have much of a choice but drive slow lol. That is more weight then it wants but it can be done. Tips would be to give it a fresh oil change and a fuel injector/carb cleaning before you get moving just to make sure everything is in good shape. Main thing i would recommend is good fresh fluid in the differentials and transfer case, this is where most of the stress will be at. My business sells Amsoil so im a little biased to which is the best. The less friction you can get between those parts, the more power and strength you'll have. Better gas mileage too. Hope this helps, good luck.

Drive it in drive, not overdrive. If the trailer is tandem, which I hope it is, Center the weight over the wheels on the trailer. Be careful and take it slow!!