i was wondering (again) how had it is to put a 350X head on a 250X cyclinder. i know its possiable but is it hard?? what would i have to do other than possibally lengthining the timing chain?? (which needs replaced anyway)

 

it does not fit the cam is different. And wouldnt it be cheaper to put a 350x motor in a 250x/300ex and you also gain a 6th gear. I heard you can put an XR500 head a on 350X motor but never the 350x on a 250/300 i have a 300ex with a big bore 405 email if that is what you are looking for