How do you tell if your 289 engine is a windsor or Cleveland?

The easiest way to distinguish between a Ford 289 Windsor and a 289 Cleveland is to look at the valve covers. While there were some exceptions and modifications over the years, this is generally the most reliable visual difference:

* Windsor: Has a relatively smaller, more rectangular valve cover. They often (but not always) feature a slightly rounded top edge.

* Cleveland: Has a taller, more prominent, and distinctly trapezoidal valve cover. These are noticeably larger and more angular than Windsor valve covers.

Beyond the valve covers, other less reliable, but potentially helpful, indicators include:

* Intake Manifold: While not definitive, Windsor and Cleveland intakes are different. Cleveland intakes are generally more "squared-off" looking and often have a different bolt pattern.

* Head Casting Numbers: The casting numbers on the cylinder heads are the most definitive way to identify the engine, but requires removing the valve covers and potentially requires a reference chart.

* Spark Plug Arrangement: While both are small-block Fords, they have a different spark plug arrangement, but you'd need to look inside.

In short: Start with the valve covers. The difference is visually striking if you know what to look for. If unsure, referencing a picture of both Windsor and Cleveland 289 valve covers will help you make a clear distinction.