Hi.. I'm rebuilding a set of 62 heads for my 400. I got a "high performance street" 1800 to 6000 rpm range Comp cam kit that includes valve springs. I suspect this engine will only occasionally see 5000+ rpm. One of the many things I need to buy are rocker arms. I see there are lots of options at Summit. Any better or worse than others or make any difference? Some better for some applications than others? Any real difference in performance in one vs. the other?