Common engine sizes for the 1987 El Camino included:
* 4.3L V6: This was a common option.
* 5.0L V8: Also a fairly frequent choice.
* 5.7L V8: A larger, more powerful option, often in higher trim levels.
You can find the engine size printed on the engine block itself (usually near the distributor or on the valve cover). The VIN can be used to look up the original specifications through a VIN decoder, though this requires knowing the VIN and accessing a service that can decode it.