Crazy Horse here my first question is what kind of stretch cruiser did u buy?
You can possibly use the simpson strong ties to custom make your own motor-mounts, see my post on stretch cruiser mounts here's the Link:
http://motorbicycling.com/f6/notice-stretch-cruiser-mounts-9582.html
You could also contact Manic Mechanic just click on his ad look at ad bar upper right side of screen!
Peace Crazy Horse.
P.S. If your Stretch Cruiser is anything close to mine you'll need to get an extra chain, good luck after you've posted 3 times here in the forum you'll then be able to post some pic's of your build!