Mattmus, 216's haven't had poured main bearings since the mid-1930's. Your 49 model will have replaceable mains with adjusting shims to fine-tune the clearance and Babbit rod bearings. Adjusting the rod squirters is as simple as connecting a garden hose to the oil pan gallery and bending the tubes so the oil spray hits an "X" scribed straight across from the nozzle.
Jerry
You will have to have the rods sent out if they need new babbit. They are not shells. The 47 was the last yaer for needing to bore the main journals. My mistake.
