World Formula and LO206 are certainly different classes. Both are based around the same block, but the WF makes about 5hp more than a LO206 (which is around 10). LO206 is a hand built, sealed Briggs Animal, and the WF has a few upgrades that make the extra power. You could probably use the same chassis and just swap the engines out, but you’ll need 2 engines if you want to run in both classes.
This topic will probably interest you.
http://ekartingnews.com/forums/topic/switching-between-lo206-and-world-formula/
GP10/CR125
S2 Semi-Pro Stock Moto - SKUSA Rocky Mountain ProKart Challenge
http://theslipangle.com/
