valve spring help

[5.9 excursion]

I recently acquired a set of industrial injection 150# valve springs brand new for some work on a guys truck, I believe they are way to big for my application and figured I could trade them for a set of 90# springs since I only want to turn 4,000 rpm. However when I got on the website for industrial injection it lists them for up to 4500 rpm so i'm wandering if they are actually to big or not. My main concern is unneeded wear on the cam. Any help on the subject would be greatly appreciated. Also I tried the search function and couldn't seem to find what i needed.

 

[Diehard Ram]

I belive those are what we call 60 lbs springs. On the seat, 60 lbs springs are 145lbs. These are an up grade if you put on an exhaust brake. For the price thats on there website, thats gota be what those are. They will work just fine. There are better things out there. Go to hamiltons site and read up on springs.

 

[5.9 excursion]

thanks that was what i wanted to know. I'm going to go ahead and use them for now since a cam and head work will come later i'll upgrade then but for now it'll allow me to run my 4000 springs.