I was picking my buddies brain at his shop today(plenty of pushrod experience, been doing it long enough that some here weren't even born yet) on the lifter and high rev engine topic, especially since there seems to be quite a few interested in it these days.
He feels it can be done, but not on any type of reasonable budget. His claim, ya it can be done, but to do it right you will spend far more than it's worth, cap the rpm at 6500 or so, and be happy, any higher isn't worth the money or headaches.
I gathered a bit of info from him.
First off, he feels link bar lifters do little good other than let you retrofit them in blocks that can't use the spider.
He's tried it every which way, including custom modded lifters, rhoades, comp cams (who grinds all his custom cams), and solids.
None of which he has been thrilled with (on stock blocks), especially on cars meant to do anything other than the quarter mile.
As far as solid setups, he's definitely anti on anything other than a race block. Last time i personally saw it attempted, it was on a B block, and it just wouldn't stay together properly for long, the high rpm didn't destroy it, but caused issues.
Switched to an R, and it was and still is fine as of today (same rotating assembly).
Not my thoughts, just someone with some experience's opinion, take it or leave it.
I've known him for almost 20 years now, and i'd say if you came to him with 7000rpm in mind, he'd either talk you out of it, or refuse to be a part of it.
I trust his opinion, but that obviously doesn't mean you have to, just some friendly thoughts on the topic.
Me personally, my last engine ran right to the rev limiter, and that was good enough for me.