Edelbrock head valve spring assembly

Our Edelbrocks came new with no cups under springs so they are not 'standard' to my knowledge; assembled head PN was 60779. I looked at these cups, but decided they were for heavier spring loads than the standard Edelbrock supplied springs.

The shims are a few thicknesses. The flat black ones under some of our springs are the thinnest and did not have any grooves. The thicker ones did have grooves. 4 intakes, all on the same head, had 2 shims (one thin black one and then a thicker silver or copper colored one), and the remaining 2 valves had just a single thicker one..... I presume selected at assembly to get the right installed spring height, which were all spot on with the installed shims.

Edit to add: If you read the instructions on some of the Edelbrock Performer heads, like for some SBC heads PN60899, they explicitly say that the spring cups come with those model heads. For the SBM heads, there is no mention of the spring cups as being part of the standard parts assembly from the factory. Not sure why.... the spring diameters and closed pressure are the same....perhaps a difference in material thickness under the spring seats? Or, it may have something to do with the stud mounted rockers on the Chevies, and keeping the spring from walking around the seats.

I can't say it would hurt to add the cups, but it will throw off the installed spring height so that will need to be somehow adjusted for with the .060" under-spring cup thickness, and you supposedly need to do some machining around the guide bosses to get them in, per the product description for the SBM heads:
http://www.edelbrock.com/automotive/mc/cylinder-heads/accessories.shtml