I just got an old supra mkIII N/A. I have no plans on ever having this thing on the streets as it is my race team's new project. However none of us have ever played with one of these. What kind of motors will fit? I was thinking small block V-8.

I'm assuming you mean a ford or chevy small block. However there is a lexas v8 swap that has been done, it is the 1uz-fe. check out the following resources:

http://supra.milisake.com/

http://www.lextreme.com/