The TRK files are different. If you compare them side by side you should be able to make the appropriate adjustments.
The face type on the body is usually different. For that, open the model in binedit, select all faces, then on the menu, goto groups > set group face type and select normal mtm type and save.
Probably best to use mtm1 tires.
I'm not sure if low detail models are required.
It's a bit of work but can be done. Kingdave converted the stock mtm2 trucks for mtm1. (you could probably use those tires if you wanted).
http://cownap.com/~truckorama/
