Cleveland V8 identification,2V vs 4V heads

There's enormous confusion about Cleveland V8 heads, so here's the definitive guide. The 2V heads (standard GT) have open chambers and small ports. The 4V heads (GT-HO) have closed chambers and enormous ports designed for high-RPM breathing. The 4V heads are identifiable by the casting number on the end of the head: genuine Ford 4V castings are D0AE-6090-N and similar. Many aftermarket heads claim to be '4V equivalent' but the originals are still the benchmark. The 2V heads are actually better for a street engine below 5,500 RPM because the smaller ports maintain velocity.