289 vs 302: choosing which Windsor core to build
Two Windsor-family engines with a lot in common — and a few differences that change the build plan.
The 289 and 302 share the Windsor architecture, which means many parts interchange and both have excellent aftermarket support. The 302 offers more displacement from the same footprint, which is why it is the usual choice for a fresh build.
Start by identifying what you actually have. Casting numbers and measured bore and stroke matter more than what the seller says, especially on a car that has been through several owners.
Decide on the induction and heads before buying a camshaft. Cylinder head choice drives compression, airflow and what the cam needs to do, and mismatched combinations are the most common reason a rebuilt engine feels flat.
Check the block for cracks and core shift before machining, and have the machine shop confirm bore clearance and deck height. On a fifty-year-old core, preparation is the build.