No, you can't. There were numerous revisions... 13 or 14 revisions of the head alone.... but an '88 may have come with any one of 5 different castings any of which may have come on an '89 or '90.
The most notable difference in the 7M lineage is that around '88 the GE received more reinforcement ribs around the cylinders and other areas were thickened... This didn't show up on the GTE though until around mid '89.
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