Good first truck purchase. It is a little simplified (one piece frame, one piece cab & sleeper, no brake details, skinny tires), but it can be detailed up quite nicely. The engine is a Caterpillar 3406, and is quite nice. Here is an article from 1991 that will help you in detailing the engine:http://public.fotki.com/modeltrucks25thscale/model_magazine_articles/car_modeller/cm08_july_1991_cate/ As for the tires, well, they could be replaced with some AMT 11:00x20 wheels & tires or the Moebius Big Rig Wheel set. There is a nice W900 P/E detail set out there, but it's more than the kit, so it probably isn't worth it in this case. Here it is if you're interested: http://www.czechtruckmodel.com/catus.php
The kit is a 1976-82 Kenworth W900, but if you remove the AeroDyne sleeper (which was introduced in 1976) you can "back date it" to a 1973. Here's one I did a couple of years ago before the reissue:
The stacks are from KFS, and I did relocate the marker lights that are molded onto the headlights to the top of the headlight bucket were they're supposed to be. The wing on the sleeper is an aftermarket item. Kind of wish this kit has a visor.