thats a good question andy and to be honest im not sure as i dont have a lot of experience just alot of enthusiasm for two strokes but when i get the cases im going to start toying around in cad to get a few ideas and it may end up unfruitfull but atleast i will hopefully learn quite a bit in the process. anyway me thinks i need to do a bit of reading up but atleast i dont think the cases were a bad investment.