Thanks Brian, I don’t judge, so I don’t what they look for. Thank you for the kind words. 

...I have been a contest judge for a few years now with the local club (both AMPS and IPMS)...viewing this thru a 1280 x 720 resolution monitor screen (aprox. 22" across by 14" tall) this is easily a a top 5 ..top 3 build.  Don't sell your self short with this one.

That does sound fun, maybe this year I can participate in the show. 

The photos show the trucks well, and I’m not seeing anything to nitpick about, but I understand your apprehension. I’ve only done one show (last September in St Ignace, we chatted about it) and it was not judged, just people’s choice. And those people were not particularly modelers, just general truck show attendees, so they were familiar with the subject matter, but not looking for someone to demonstrate modeling skill. Their votes seemed to fall towards “general effect” - things that brought a smile to their face - something that your models will certainly do. The other truck modelers there were very supportive and non-competitive. It was just a bunch of guys enjoying truck models. 

Thank you sir, maybe some day I will take a couple of these trucks to a show. Problem is, I can see every mistake and I know everyone else will see them as well. 

It’s a beauty. Lots of custom parts. Updating the power with things like a charge air cooler is a feature a lot of guys miss. The Cummins logo is a nice touch. I enjoyed watching this come together on the other forum. You should definitely consider bringing this to a show.

Just finished this build today. Nearly every part was modified/ replaced with 3D print or scratch built. 

Hi! For 1/24 and 1/25 scale truck parts, check Thingiverse, MyMiniFactory, Cults3D, and Printables by Prusa. You can also use CAD software like Fusion 360 or FreeCAD to design or scale parts yourself.

appreciate your in put ......I just presumed that finding info. on the Mack would be like my previous findings (dimensions) on the 60's era International Harvester DCO 405 Emeryvilles and VCO A 190's as well as the Ford C series cab overs....discovered volumes of useful information.   Looks like I will have to add 12 to 18 scale inches to accommodate the tank body...still undecided about adding a pusher axle.   

Sorry to hear your search hasn’t yielded much info. I unfortunately can’t offer specific as to wheelbase offerings, but I have stretched frames to accommodate bodies. I definitely agree that you can just place the tandems where they “look right”, and go from there. Sort of, “reverse engineer” the project based on what your eye tells you is right. That’s ultimately what you’re aiming to please - your own opinion of what’s realistic based on what is sweet to your eye.