Help with Valvesprings and valve float. Noob

Hey guys I'm still learning alot when it comes to valve train geometry ,so bare with me. I'm still having an issue with valve float @ 5800 after installing new springs and I wanna make sure the springs I installed were the correct ones for my application, and if I even did it right. First of all my engine combo:
408
Eddy heads. Ported /super Vic intake
Lunati 60405 HYD flat.
242/252@50
Around 600 lift with 1.6 roller rockers.
Now the cam card list the use of lunati springs with these dimentions installed @ 1.65
We couldn't get thoes springs, so my "engine builder" told me to get the comp 987-16 with these specs:
I was told to install them @ 1.8 ( the same as the factory eddy springs were installed at)
Now this was over a year ago when I little knowledge about valve train and just learning from what I was being told to do.
Turned out I still had the issue, so i started thinking maybe we had an ignition problem or something else was going on. I live in Calgary where we get short summers and not much play/track time to test the car and see what's going on. Long story short after replacing all ignition and fuels system I find myself a year later coming back to the conclusion that it must be mechanical and getting valve float/lifter pump up....
I'm sorry if Im missing information or doing something completely stupid but I never did learn much about valvetrain..I've just been going by what I've been told to do and never had an issue go on this long that can have so many different causes.

FYI. What this misfire/valve float feels like
-happens in every gear above 56-5800 rpm
-feels and sounds just like hitting a rev limiter.
I have a data log recorded if anyone needs to see it

Thanks guys.

Edit because I copy pasted specs from Jegs.