Same springs I put on my stock 452 heads, 440 6bbl, heavy rods, steel crank, valve reliefs notched flat top pistons engine. Definitely a Purple Stripe cam, most likely the 292° /.509 cam. I also put the CompCams hydraulic flat tappet lifters in at the same time, and 10° Comp locks and retainers.
Old springs were worn out, weak pressure open and closed, as I suspected.
With the new CompCams parts, and the same old cam I described, my engine
wants to, demands to go to 6,200 RPMs.
I have my shift light set at 5,800 and the rev limiter set at 6,200.
I can't wait for a chassis dyno session to see if what I "know" my butt dyno is telling me is true, or how far off I am. It would seem like the engine power would roll off sooner, and it may, but it sure doesn't feel like it!
Good luck!