Thanks for the input. Having just started with both programs I have realized that I a long way to go. I had the model without the mount and was happy enough that I imported it into my plans. Somehow I managed to delete the original blender file when cleaning up some leftover practice files.
I imported the .obj back into blender to work on it and a lot of the separate items were now joined. like, the motor, core and louvers were now all one piece. I need to pay more attention to my clearances. I also usually leave most of the color out in blender unless it is something I need to make the object non-transparent like the heater core in this example. Most models are easily modified in sh3d although they can have a lot of parts.

I find a lot of .obj models I import are much smaller when imported into sh3d. I should learn more about the scaling of the 2 programs and how they interact with each other. I use feet, inches and fractions in sh3d. They all seem to scale just fine. I hadn't thought about including the .mtl file until you mentioned it. I am still really new at all this 3d stuff.