Cr125r 2002 ultimate build(hopefully)

Hey guys big bad update. Once I stripy the bike to the frame I had a track day the coming weekend so thought I’d do nothing to simply just put it back together new plug new oil new coolant and take it to the track to see how it really does ride. But this is where it went downhill. That exact night this bike was stolen along with my trailer. They decided to leave my mountain bike rm125 and crf250 although. This is why I haven’t been updating sorry guys. I have been on the hunt for another cr125 or 250 but a bit newer. I have managed to find another cr125 2002 for very cheap. The same guy also has a cr125 1999. So I was wondering if I would benefit anything from installing the 1999 motor into the 2002 frame? Otherwise I’ll just stick to the 2002. Cheers guys