One more follow up comment on the 3:73 response - yes, I'm very happy with it, and part of the reason is the 4:10 whine all the time at higher revs when hauling, which the 3:73 does not have. And the better gas mileage ... not a big issue, we get maybe one or two MPG more, but it's the whine I didn't like when under a load in the 4:10 vehicles.
If you tow a lot, or in hills, maybe the 4:10, but I've taken this 60.L w/3:73 up the Rockies numerous times - and never cried a tear over my choice. BUT, if I did the Rockies a lot, then I might reconsider, as it does work at that mountain-climbing, but it works and hauls it. That's what's important, and the rest of the time, it cruises - flat roads or light hills it sings along just fine.
If I had it to do over - I'd pick the same combination again, after 197,000 miles with this one, 75% hauling or towing.
