Rear axle ratio question
 

I am looking at replacing my 95 Chevy K1500 with a new 2010 while they are still available with the incentives. Already not a ton to choose from. Two I am looking at are both K1500, one ext. one crew, both 4x4. Both have 5.3L, 6 speed automatic, trailering package, heavy duty cooling and high capacity air cleaner. The crew cab has a 3.42 rear axle and the ext. cab has 3.08. I live in Michigan. The heaviest thing I trailer is my "big" boat at around 5,000lbs inclusive of trailer. I don't haul it far- only about 10 miles to Saginaw Bay. Occasionally 50 miles to Higgins Lake. I will likely get a new boat in the same weight range in a couple years to tow to FL in winter for a month or two. Very unlikely to ever tow anything heavier. The vast majority of the time I haul anything with the truck will be in the bed and/or cab, not towed.
My 95 has the 4.3L 6cyl. with 3.73 rear axle. It tows the boat ok, as long as the roads are pretty flat, although mileage drops way off. As soon as I get into any hilly roads, with any weight trailer, the truck feels way underpowered. It wants to shift constantly unless I downshift manually. When I do that I seem to have to run pretty high RPMs to maintain highway speeds.
I can't decide between the two trucks. I can find things I like better about either body style. With the bigger engine, would both trucks do a better job of towing than my old truck, or should I stay away from the 3.08?
I apologize for the length of the question. Thanks, Al

i'd personally go with the 3.42. with the 6 speed trans, you'll still get good mileage, but the engine, trans, and rearend won't have the added strain when you do tow.

I think I am leaning that way. I tend to keep things for a long time and have been disappointed with the power of my 95 for about 15 years now. Don't want a repeat. Thanks, Al