416 Burning oil and the road to redemption

I'll betcha that some of the rocker to spring interference comes form the idea that the roller has to be exactly centered over the valve stem when viewed as in B3RE's 1st pix. It doesn't; the design of the roller system takes a care of any small offsets. Springs don't always stand up perfectly straight, nor set perfectly centered under the retainer, so some side to side offset may be necessary.