Help with Valvesprings and valve float. Noob

The motor that the dyno sheet I posted belongs to came to me because the owner was unhappy with the power, and rpm capability.
It hadn’t been on the dyno before, but the owner said it basically wouldn’t go over 5100, which was confirmed with a chassis dyno test, where the power fell off a cliff at that point.

I swapped it over to a solid cam and shimmed up the valve springs from 115 on the seat to 130.
Other than longer pushrods to fit the new solid cam & lifters, the rest of the valvetrain remained unchanged.
As you can see by the sheet...... no problems at 5100 anymore.