I have a 94 Monte Carlo 640. It cavitates. i was told it needs a wear ring. I purchased a used one but my mechanic says it does not look good. Part number is 0673-126. I have a brand new wear ring which was advertised incorrectly part number 0673-119. my question is there a way to measure the ring and what should i look for? and Is it possible to use the other part number? the difference is probably a 1/4 inch in length?