Do you realize that once you rebuild the bike, you will most likely have way more invested than it is worth? This is especially true if you create a "frankenbike" with a larger engine. If you plan to keep it forever and never sell it and/or it holds some sentimental value, that is a different story. However, if you think you may sell it in the future, you will likely lose alot of money. I have experience with investing more in bikes than they are worth. On the Frankenbike topic, there was a guy here in Dallas selling a CR125 frame, forks, etc with a 200 4 stroke mounted in it. He was selling it on Craigslist..I watched it, and it took about 6-8 weeks to sell and he got alot less than the original asking price.....just something to think about.