I really like this guys work. Steve "Carpy" Carpenter is his name.

This is his web page.
http://www.cb750cafe.com/There are some great pictures on here. Especially if you you are like me and have a real soft spot for 70's and 80's Japanese 4 cylinder bikes. Steve here seems to prefere the Hondas, but i think you could do this with just about any of the jap 4s.
I want one
