There is alot of work ivolved in making them work properly. You will need to make a manifold,cable system wich is critical for even throttle opening. The fuel set up is very hard to get right because motorbike carbs are gravity fed so you will need to feed fuel out the main tank into another tank simalar to a surge trank you see on efi set ups. But that will have to gravity feed the bike carbs. I have heard that they work very well in off road set ups ie buggy racing. You will probably need 4 carbs off a 350cc dirt bike. Makuni are good but very expensive for new ones. I use twin 40mm webers & would recomend them to any one because when in good condition they are very tunable. People will bag them out but go to any historic race meet & look at what guys there use & that will give you some ideas on what carburation to use.
I hope this info helps

Coops