How much cam end play does the engine have?

How about to much valve lash? could that pound out the needle bearings?

It has been mentioned to me the pushrods might be a part of the problem. There is virtually no give in these, where the 3/8 heavy wall pushrods probably were easier on the rest of the valve train?
For those interested, the lobe numbers on the cam are
Intake 1625 320-8

Exhaust 4247 336-5. The rest of the numbers are in the first post.

If you want the bushings, it's the red zone lifters with the EZ roll option.
I don't know if the springs will have enough pressure without the inners, but if they do, it's fine to run them that way.
You should check each spring for it's actual coil bind height, and go up from there to determine the installed height.
I've seen examples of those triple springs where they start to stack up before the coil bind spec, and when that happens you'll see the pressures spike right up.
It's really best to avoid that if possible.
The coil bind spec for the 947 is 1.145, but I've seen where it's closer to 1.180-.1200 on occasion.
In your application, I think I'd probably have went to a 2.050 installed height to use that spring, although that can be tough to get on a 440-1 head.

My .02 on the cam........

It's an older super stock intake lobe, designed for max power in a high effort/high maintenance application. On top of that I'm pretty sure it's old enough so it doesn't have the benefit of spintron analysis during developement.
The exhaust lobe is old too, but those are pretty stable.

I would regrind it into something more modern that was developed for a lower maintenance, bracket type application, with the understanding there could be a slight reduction of power as part of the trade off.

My suggestion:
-smoother lobes
- 1.7 rocker
- red zone lifters
- spring pressures in the range of 300-320 seat/800-825 open

The big cube motors I've done use that combo and those guys don't usually touch anything for 250-300 passes........ And that's without the high end lifters.