Do you still run the spray bar valve covers?

If not....... maybe you solved one problem by replacing the aggressive cam, but canceled out the good you did there by removing the valve covers.

If you still have them, I’d put em back on.

I can’t remember for sure since I built those motors several years ago...... but I think all but one got 3/8” x .120 wall pushrods, and one got 7/16” x .080.
They also just run the plain Jane Comp lifters, and get replaced when the motors are freshened.

They’re all just basic bracket builds, and have been quite reliable.

I like the bronze washer idea.

“If it were me”........
And the valve covers didn’t improve the bearing life, my next step would be to try a cam along the lines of the .775 lift one that’s got 1000+ runs with no failures to rule out the possibility of harmonics killing the bearings.