At what point would you step up to ferrea hollow stem valves

It seems that their has ben little or no discussion on light weight materials used on sft's and push rods and materials. what about rocker geometery and weight? I only rpm to 58 to 62 hundred and I use Trend H-12 solids and trend Ball Ball thin wall p-rods that are not reccomended for my package. I have machined the piss out of my Hughs rockers to lighten them and oil through the rockers to the p-rod ball just to not have the weight of oil filled p-rods. I also have and LIKE the B-3 Rocker correction assy. that takes alot of the stress outof the complete assy, meaning less spring pressure/weight. I use suprisingly light Manley springs, Ti retainers, H13 locs and now I am going to go to Ti intakes that will almost equalize the the int/exh valve weight, very close. 12lb. mccloud flywheel, 512-B kit w/light weight crank, 6.8lb sfi damper. BHJ. This thing spools up faster than i can shift in 1 and 2 gear. And yet I still look for ways to shed weight.looks like I have to face plate the old 18-spline now.I would like to have big heads but I'd better stay with what I have.