If you have connecting rods with replaceable bearings, (1953-62 235 and 261 engines) the first thing you will need to do is measure the crankshaft to see if it's been reground to an undersize to correct wear at some time in the past. The standard size rod journal is 2.3115-2.3125 inches. Undersize bearings are readily available in -.010", -.020", and -.030" sizes, with the occasional .001", and .002" undersizes available to compensate for minor wear without regrinding a slightly worn standard-size crankshaft. The crankshaft journal MUST be smooth and round, regardless of the undersize, before fitting new bearings. If the crankshaft rod or main journals are egg-shaped or scored, the crank must be reground to a smaller undersize, or the bearings will wear out rapidly. That involves a complete engine teardown and overhaul. There are usually plenty of bearings available on Ebay at reasonable prices, so once you determine what size replacement bearings you need, don't get robbed by one of the "antique" parts vendors. 235 rod bearing sizes didn't change from 1953 to 1962, with millions of replacements made, so they definitely are not scarce items!
Jerry
