Re: Parts compatibility for a 1995 90 horse
OMC settled/standardized on the 99.6 cubic inch block for all their V4 engines from 1979 on. There are great similarities in all these V4 blocks all the way up to the end of them in 1996. In the case of your two model numbers above, the pistons and rods all supercede to the same part numbers, so they are interchangeable. The crank bearing and head are the same part number. The main center crank split bearing is the same part number between the blocks-which would mean the cranks would interchange, yet the cranks are not identical. That could mean the spline configuration may be different for the drive shaft-or something similar to that. Having said that, my concern is that you've identified one engine as an 85 hp engine, when it's model number clearly indicates a 90 hp engine. If you have an incorrect model number on the older engine, or a substituted 85 hp block on a 90 hp midsection, it could be a problem. For example, if your older engine is actually a 1978 85 hp engine-it is only 92.6 cubic inches and now many of the engine parts will not match up to the larger 99.6 cubic inch 1995 powerhead. You may want to compare the model number on the top of the older block to insure it is the same as the serial/model tag on it's transom bracket.
