thanks guys you just helped me without knowing it , i was just reading through this thread and thought i better go check mine .
i am getting an 076 ready for milling and i have got all the bits to change it to 3/8 from a guy here in oz anyway went up to the shed and checked out the rim sprocket and it never had the little cut outs to slide over the oil pump drive , but it has now i fixed her with me trusty dremel and it can now slide unimpeded .also had to shorten the chains they were supplied to long for the 50 inch bar but all is good now . all i have left to do is rig up an aux oiler and i am ready to go .
i did have the clutch let go and exit through the side cover but i have that sorted now .