I believe that engine is the basis for the LO206 kart racing engine. You might look there for some ideas and inspiration.
As mentioned, please be safe and install the high performance parts inside before you start shopping for a motorcycle carb.
Make sure you go through those engines carefully. They might be missing gaskets, bolts, washers and bolts might not be torqued. They have probably been taken apart and put back together dozens of times by students.