I run the Jesel 1.7 rocker system with individual shafted pairs. On the thought of what causes the .030 deflection, virtually every component contributes. Starting with the mounting bars, 5/16 mini shaft hold down bolts , to the 5/8 rocker shafts, then the bearings in the rockers, then the rockers themselves. Start adding up the .000+ movement of each little piece, then add .003+ cam flex (documented!) Compression in the pushrods and lifters, and it ends up where it is. All this was hard to wrap my head around till i was playing with my rod bolt stretch gauge one day, and realized i could steetch a rod bolt by lightly torquing it with my finger tips! It actually stretched .0002 with out much force at all .