Really really neat truck! Love the front mounted spare, reminds me of the '74 camper special my grandpa had many years ago, he had the spare on the front. An orange truck, maybe a reddish orange? Wonder if that was a factory color now that I think of it?
The wheels are not good, but I also noticed the aero skirts sit too low, having a larger gap below the hood and cab than should be when looking at photos of the real thing. It can be fixed by mounting them higher on the fuel tanks, possibly shimming them with styrene strip. I fixed mine by not using the kit tanks at all, and mounting them differently. I have the chassis and cab complete, I need to update my on the workbench thread. Also, The instructions show the wipers mounted the wrong direction. Again, looking at photos of the 1:1 really helps.
I also experienced a warped hood issue, and despite spending way too much time to correct it, it still isn't perfect. This plays into the worst issue, the hood and cab fit. The only way I got the hood to sit down right when closed was to first mount it on the hinges and then bring the cab in and adjust it so they both mate up together, and use a small magnet on the firewall and under the hood to get good closure. This looked good, except for the fact that the cab was tilted forward slightly, but enough for me to notice. This has bugged me for a while and halfway through writing this post, I went down to my workbench and started fixing it. I reworked the rear cab mount after cutting it off with a dremel, re-gluded it level. Of course, the hood doesn't fit now, so I have a choice, rework or remove the hood hinges. If I don't use them at all, the hood is removeable and is held nicely in place by the magnet, so I can display the engine with the hood off. Might be the easier option.
Other than that, from a kit design perpective, they used an incorrect chassis and engine from past kits. A common problem, and I know they did it to save money. If the engine bugs you too, then it can be swapped out for a Series 60 or modified to look much more like a Cummins N14.
It sounds like all bad things, but it can be a nice model of a nice truck.
Class A Resin has rubber intake elbows as well as a bunch of other Auslowe parts. He had an extensive line of awesome aluminum parts, but I don't think they are available right now. Ben is great to work with.
American Industrial Truck Models (AITM) is also a good source for general aftermarket parts.
Double Take Replicas is also a great source for resin parts and tires.
Rhino's items are great too.
For photo-etched details, Czech Truck Model is the best. Kit Form Services (KFS) also has good stuff, as Clayton said.
Another source for real aluminum parts is Michael Cherry from the UK. His company is MCA Model Accessories. He has horns, stacks, etc. He can custom make just about anything. I have an excellent set of polished aluminum scale 8" curved tip straight pipes he made based on the truck in my profile pic. I sent him the photo and specs, and the cost and time was reasonable.
All of the sources have websites you can find in a simple search. Most are ordered by email and paid through paypal.