J heads and Lunati cam question

I had the same issue last year with a my lunati cam

638-00043LK
Adv. Duration: 292°/292°
Gross Lift: .480''/.480''
RPM Range: 2500-5500

I ordered a new set of lunati single springs. I hope this solves the problem or I will taking my other set of J heads to have them cut for double springs.

I used the same spring for the same comp cam and I had one exaust valve float at about 5600 to 5800.

I suspected that it is was a slightly sunk exaust valve but, I am changing the springs just in case.

Pete