Use only the 3 original spacers...
EDIT: It looks that I'm wrong, those 1.5mm spacers are probably needed to match the size of the stock plastic uprights. Make sure that the size of uprights with (stock) spacers is the same with stock and with hop up uprights! For the F104 arms You do need F104 king pins so that should be OK but don't forget to tighten the set screw in upright that holds the king pin...
thanks dfx..
so it will be 3 spacer on top and 2 spacer on bottom...since the hop up upright is shorter than the original plastic upright.
one more question... the screw on the upright, its suppose to screw it to center of the kingpin? which have line for e-ring? or it can be anywhere...
thanks