What is the engine size of a 1993 Chevy mark 3 conversion van?

There's no single engine size for a 1993 Chevy G-Series (which is what the Mark III conversion van is based on). The 1993 Chevy G-Series vans came with a variety of engine options, including:

* 4.3L V6: This was a common choice.

* 5.0L V8: Also a popular option.

* 5.7L V8: A larger and more powerful V8.

* 7.4L V8: A big-block V8, less common but possible.

To know the exact engine size of a specific 1993 Chevy Mark III conversion van, you'd need to check:

* The vehicle's title or registration: This often lists the engine displacement.

* The vehicle identification number (VIN): A VIN decoder can reveal the engine.

* The engine bay: The engine itself will have a sticker or casting indicating its size.

Without more information about the specific van, it's impossible to say for certain.