2005 Silverado Rear End Ratio and Towing Question

[Sierra_guy]

I recently bought a very well maintained 1 owner 05 1500 Crew Cab 4WD Z71 pickup.  The guy I bought it from had just about every receipt since it was new and even still had the window sticker in the glove compartment.  After I got home I started looking through the documents and notices the window sticker shows the truck has a 3.73 rear end. I looked at the owners manual to see what it's rated to tow and a the 4WD crew cab only shows one rear end ratio of 3.42.  So I looked at the RPO codes in the glove compartment and shows to have a 3.73 I (I think it was GT4 It's been a few weeks).  I also noticed that the engine is turning about 2,000 RPM at 70 mph.  This matches my 04 Yukon that also had a 3.73 rear end.  So what is tow rating of this truck.  Everything I've found says it should have a 3.42 rear end.

[r1byker]

You'll be fine with a 3.73, which is easier on the powertrain than a 3.42.  The tow ratings have more to do with with the suspension than the power train.  For example, my '05 1500 Suburban has a tow rating of 7,000 lbs. but in the small print it says that's with a proper weight distributing hitch.