I remembered something I did back before I knew any better.......

I had enountered a valve float type situation with a ssh-44 cam I tried.
The motor had some Crower springs in it, and before I installed it I called and asked them if they felt those springs were adequate for the cam, and they said the springs should be fine.
The motor would just flatten out, at an rpm quite a bit lower than what it did with the old Crower cam.
I tried all kinds of things related to fuel and ignition, nothing made any difference.
I brought the car to the local speed shop I was buying stuff from at the time and took the owner for a ride.
He felt it seemed like valve float and asked me about spring pressures and installed heights..... which I couldn’t answer.
He said to put some shims under the springs and see if it helped.
I installed a .060 shim under each spring, and it totally fixed the problem.

About a year later I want to install a solid lifter cam, but it needs dual springs.
I have some new heads to put on which already have the spring pads cut for the dual springs.
I’m working at a parts store, and we sell TRW engine parts, so I look up some dual springs in the performance parts catalog for a 440.
I thought....... hey...... if one shim was good..... two will be better!!

So I assemble the heads with my new dual springs and two shims under each one.
There was no soft springing for cam break in..... i just fired it up and ran it at 2000+ for about 15 mins. No problems with break in.
I ended up trying 4 different cams with the heads set up like that...... no problems with any of them. And the car ran pretty well too.

Years later when I’m working at a machine shop, I pull the heads apart for freshening. Everything was holding up fine....... and I had a chance to see how the springs were set up.
As it turns out....... they were a pretty high rate spring.
The highest lift cam I had run with them was around .550, and the springs were like 155 closed/450 open with that cam.

Sometimes ignorance really is bliss.