The "real problem" is apparently bad rocker arms. Way too often, they try to make a small change in an existing product (Olds V8 to Windsor, BBC to Ford L6) to save R&D, but they don't have anyone on staff competent to say "wait a minute, there are other differences...". Rocker arm geometry (not application) was settled engineering 300 years ago, they're not paying attention.
Don't modify them? Throw them away? And replace them with what? Ask the manufacturer "do these fit?" What answer do you think you'll get? Is Barton, T&D, and Jesel the answer for everyone?

We have tolerated crap from even the most expensive sources far too long to expect NEVER to get a part that needs adjustment, etc.

[/rant]