I been looking for buying a truck for some time now and have a good deal on a 2005 Chevy duallie CC. Is this a good truck to tow with? My boat and trailer is 11.660lbs dry and the trailer is rated for 15K. I know I have to derate my trailer to make it legal (13K) and I will. I also plan to mount a WD hitch (since Sydaways talked me in to it...). Just looking to see if the 8.1 is a good option. I know mileage wise a diesel is a better option, but I drive about 2000 miles a year so the savings will never offset the purchase price for me. Any experience out there that will like to enlighten my knowledge?

super combo! Not a big difference in mileage per gallon compared to duramax, specially when towing. Plenty of power, that is what you need for your low mileage a year. I have a customer pulling 15000 (up to 20000) each single day of the week and he would not change his trucks for anything else.

What is the gear ratio in the truck? That will make a big difference.
GT4 on the build sticker is 3.73 (check the glovebox)
GT5 on the build sticker is 4.10

Is it the 5 Speed Allison Automatic or the ZF 6 Speed Manual?

Having towed with both the 8.1L and a modern Turbo Diesel, I can tell you that there is quite a noticeable difference in power. That setup should work/tow great for a long time, but a diesel is better. "offshoredrillin" here on OSO has the same truck and he loves it.

Not sure about the rear. The plan is to put an OX locker in it, and change the ratio to what is needed could be done in that process. It does have the Allison 5 speed.

I'm sure it already has a locker, why change it?

check the glovebox sticker for G80 and GT5

if it has both, buy it

it'll pull a house down

put 265-75-16E tires on the front, and 235-85-16E on the rear

get a Putnam 15k hitch and the class 6 carrier below

http://www.airsafehitches.com/receiver_hitches.html

then get a big tank from transferflow

http://www.transferflow.com/GM_fuel_tank_systems.html

great combo we have 2/ 8.1 Avalanches and a 8.1 Suburban as well as 8.1Hds we tow everything from 343 cobalts to 47 Fountains and every thing in between I love the combo if you dont mind the millage Nothing better as a tow package imho.except a Duramax!

Are the aspect ratios the same on the 265s and 235s?? if not wont work on 4X4 wont matter if 2X4

What does G80 and GT5 stand for? What about 19,5 Alcoas? What tires if 19,5? Interesting hitch, might go with something like that.

19.5's pull the motor down too hard...

stay with 16's or get some '08 17" takeoff rims/tires

265-75 and 235-85 are virtually the same height

GT5 is 4.10

G80 is posi