I would say that some disassembly would be in order. You would want to measure cylinder wear to see if a rebore is necessary. It would be good to examine the bottom end too to see what is needed there. If you want to pay for a complete rebuild, a place like Parry Automotive could do that for you. I have used them to bore both of my 216s. By the way both my 216s are thriving in the respective vehicles.
