What is the towing capacity of my 1998 chevy tahoe LT 4dr,2wd, with a tow package?...I have heard it's 6000, 6500, and 7000, mostly 7000lbs. Also can I tow in overdrive on flat surfaces at 55 -60 mph?

 

Look at the sticker on the driver door. Suburban 1/2 ton is 6500

 

or the owners manual...all depends on the engine, trans, differential, drive configuration 4x2, chassis package, tow package.

as for towing in overdrive...depends on the strength of the applied clutches...if a band is used in od as the holding member, I wouldn't. the main purpose for cancelling overdrive is to reduce constant shifting and the heat build up associated with it. Maybe someone familiar with your trans can give you a better answer.