Magnum head question with +.100 longer valves

I'm working on a set of eq magnum heads with plus .100 length valves .
Problem is the valve springs. Installed height is 1.700 and the seat pressure is low.
I guess the cam is .553 lift with 1.7 rockers.
The springs are at coil bind before max lift.

Has anyone had success with this & if so what springs or should the customer just go with a stock height valve.