You're right. If you look at the pictures of the older Pierce Dash's, the wheel arch is much closer to the tire. The newer ones have a bigger gap. Almost looks like someone put too small a front tire on the truck

Location: Smyrna,GA

That's the Tak-4 Suspension difference.

I just unboxed mine and immediately noticed the same thing. After comparing the model to the Wichita Pierce, the Fairfax cab sits a smidge higher. Since it looks like both models use the same chassis and cab castings, it looks like the different chromed base might be the source of the jacked up front end. It's a shame really, since the rest of the model seems particularly well done.

Here's a picture of the actual engine. The wheel arch on it doesn't seem as big.
http://www.fairfaxfireofficers.org/images/Apparatus%20for%20Stan/E440%20-%2005%20Pierce.JPG

Location: Smyrna,GA

Wonder why Code 3 stopped putting the mud flaps on models (other than $$ ?)