A Kenworth T600 can be purchased from a truck dealership and from Truck Paper, Truck Trader, Ranges Trucks and Accessories, Truck Sales, Ebay and Commercial Trucks.
It's 3 lbs, 12 ounces for the T660, and that's what it should be for the T600, as well.
right hand side of driver door
Peterbilt never made the T600. The T600 was built by Kenworth, and it ended production in 2007, at which point it was replaced in production by the T660.
Between 16,000 and 18,000, depending on options. For example, the engine displacement will affect weight. If you get, say, a C12 or C13 Cat engine, it'll be lighter than the C15 or Cummins ISX. The transmission.. an 18 speed will have more weight, etc.
You open up the steering column and find it in there...
There are many types of semi trucks available for purchase from Kenworth Trucks. A few of these semi trucks are T880, T680, T600, T700, W800 and also a W900. Kenworth dealers will also sell used trucks from other manufacturers which were traded in. Aside from selling Class 5 - 8 Kenworth trucks, some Kenworth dealerships are also dealers of Hino trucks.
It'll be in the vicinity of 11 gallons.
The tallest point can be up to 13'6... typically, they'll be between 13'1 and 13'4 with a stand up sleeper.
Call a Kenworth dealership, give them the last six of the VIN. They should be able to tell you what it was keyed for from the factory - if it was re-keyed at any point, they won't know.
Not really sure what you mean when you're saying "outlet". If you're talking about 12 volt outlets, yes, it has those... how many and exactly where they are depends on the model year (1986 - 2007 were the available model years for the T600). If you're talking about the block heater, that depends on if one was installed on the engine... those were an optional feature, but are pretty simple to install if you want to install it yourself. If you're talking about a 110 volt AC outlet via an inverter or APU, then those are aftermarket installations, and won't come stock from the factory.
Used Kenworth trucks will be found at many truck dealers. Kenworth is one of the most popular brands. Blue Ridge Kenworth is the local dealer but they can also be found at places like Ryder.
Commercialtrucktrader.com is an excellent resource for finding used trucks for sale. Here is a link to one for 31,900: http://www.commercialtrucktrader.com/find/listing/2007-Kenworth-T600-99512860