* Small-block V8s: These were the most prevalent, with various displacements like the 5.0L (305 cubic inch) and 5.7L (350 cubic inch) being common.
* Inline-6: A 4.3L (262 cubic inch) inline-six cylinder engine was also available.
* Diesel V8: A 6.2L diesel V8 was an option.
Without knowing the specific trim level or options of the particular 1987 Silverado, it's impossible to say definitively which engine it has.
