[vector1]

i've had the solid and hydraulic rollers.

aluminum block--hydraulics. the block expands quite a bit and not always the same in each cylinder. it is an adjust when hot then let cool down and recheck and adjust each one to that spec, and if you go back and check the other cylinders when hot they will possibly (highly probable) still be different. if you try to adjust them all hot the engine will be cooling between when you started and ended.

steel block, better chance of solids for me, but for me hydraulics are hard to beat.

giving up 1000rpm at the top is a just a few seconds quicker shift, and giving up some hp at the upper end you will never know. with some good springs and lifters people are regularly turning up to 7g rpm on some of the engines, don't know if the fe is doable.