The 1996 starter is a different starter from the 1988 and will not line up, there are a few different types of starters also in 1996 that are made for the different size engines such as the 4.3, 5.0, 5.7 liters and Diesel engines.
Make sure you have the right year in starter and engine size starter, using the wrong starter can result in replacing the Flywheel.
Good luck and you can use your Vin number to get the right starter for your engine.