I forgot to mention, The old Smith Miller B61 Mack trucks are 1/16th scale also. Didn't Travis build a tow truck out of one of the L models?
Some collectors of these great trucks will frown on using the cabs for custom work. I always had an idea of building a Mack heavy spec dump truck using the "L" Model cab with custom fenders.
A quick search came up with this:
http://www.ebay.com/itm/1940s-MACK-L...item54191065ff