Great thread. I love the intermittent chit-chat. Anyway, I had a 1975 450SE that developed the same ticking as others noted, due to one of the lobes eating into the rocker face, big time. It actually wore a scallop into the surface, so you got a 'tick' when the lobe passed over the beginning ridge of the dish, and another 'tick' as it passed the end ridge.
I solved that temporarily by filing/buffing the lobe smooth (obviously past the hardened wear surface at that point) and putting in a new rocker. I think I got about 1 year of summer driving before the ticking returned.
The final solution was a used engine from which I transplanted the 2 pristine cams and their mating rocker arms.
If I were you, I'd put all new rockers in with the used cam if the originals cannot be matched, IF the over $300.00 cost for 8 rockers was justifiable. Otherwise, you could possibly get away with good used ones...it's a tough decision against which you'll have to weigh in a number of factors.

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1986 560SL
2002 Toyota Camry
1993 Lexus