I'm not familiar with the bike you described but I can tell you that if you have a way to post some pics of your bike there are many of fellas on here that can look at the pics and tell you if you may be facing any bumps in the road when mounting your engine, I would think that you should be good with the room issue because it is such a large frame, but you may have to build a custom front mount for the engine which is very common when ussing these China made motorbike engine kits, does your engine have a pull starter on it? if so that will cause youan issue that can be remedied by either mounting the engine higher on the frame so the pedals will clear the lower part of the pull start, or you will have to have wider cranks or shorter cranks on the bike, if your engine doesn't have the pull start just disreguard all I said about the differnt size cranks and mounting the engine higher it will not be an issue.
Post some pics if you can.....and I'll bet you can get all your questions answered.
good luck with your build....!