I used this roller cam in my 88 5.7L (still have it sitting on the shelf), I could get it idling nice at ~750 RPM but, you could tell it wasn't stock. Still had enough vacuum for my brakes too.
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Comp cams suggested I use CCA-986-8 springs. With my heads, I had to use CCA-4770-8 Locators. For retainers I used their CCA-743-8. I know some folks used "beehive" springs too. Just give your cam company a call and ask them. YMMV