Predator is a great machine. I have an 04 that I completely rebuild ground up including motor last winter. Depending on what your going to do with it will determine what you should do with the motor. What was the reason it was tore down in the first place as that will also play a factor in the rebuild. First thing if you dont already have one is order a shop service manual for the bike as your going to be doing alot of reading while building. Now over on my site
Polaris Pro Riders my co-owner sells a dvd on the fuji motor and the complete tear down and rebuild of this motor. There is alot of knowledge over there