The original part # is 41-62. I order one with the new part# 321788. The new seal is has a different depth size than original. It is about half the depth than original. Any ideas?
That is the correct replacement seal. You can use the thinness to an advantage by installing it at a different depth so it rides on an un-worn area of the shaft. Or, better yet, use two of them if there is enough room. Install the inner one lip toward the oil and the outer one lip toward the water.