I found a backhoe at the Gym. I like to set up the reference photo on one page so I can see them in max while I work. An use the front, side, and back to scale from. Its always best to keep your reference photos in alignment and the proper scale ratios
3d backhoe in Max
I got some nice textures from these photos.
backhoe 3d
Low Poly Backhoe with Trailer
Technical Graphic Design and 3D Media 
That looks like the image igloo mode in SketchUp. How do you get the photos so they are aligned and scaled accurately? Guess the big tire could be a reference point.
I lay them out on a page in photo shop and use the guide to make sure that key areas line up. Then apply to a plane and dupe. put the two planes at 90 deg and if the photos are all aligned then the images wont fight each other. If you remove all the perspective in your images it is easier
I only had included the 3/4 views on the image for reference. That way I have the reference right there to look at while I zoom in and out
I see, very cool!