Cowboy

Just wandering if anyone knows, I need to source some parts for my '79 xs250 but that is proving quite difficult. Mainly i need a right hand exhaust (just the end can) but i cant find one anywhere. Parts for the 400 are easier to find, i was just wandering will the parts (exhaust) off a 400 fit my 250 and will it alter the power dramatically (good or bad). If anyone can help me that will be greatly appreciated. Cheers in advance, Chris