583 vs 690 heads

[cabriolet409]

I've done some reading on the differences between these heads, but could anyone shed some light on why Chevy switched from 690s to 583s? Are they considered essentially equivalent in performance?

[fatride]

583s have more material under the valve spring pocket for increased valve spring pressure, this is the only difference that I know of. Maybe someone can add to this

[skipxt4]

When Chevrolet started putting Z-11 cams in the 09's, they changed the heads from 690's to 583's to get more valve lift, without coil bind. Skip:)

[cabriolet409]

Can anyone speak to the relative market values of the two casting numbers? Are they about equal in "selling power", or does one set have an advantage?:dunno

[CDNpontiac409guy]

Yes, as Fat said, the spring pocket is stronger... it's also about .050" deeper, allowing for a taller spring, accommodating the .556" lift "late" 409 / Z11 cam profile.
Performance wise, I don't believe there's a difference.
583's seem to sell for about 15% more.