I know the subject is lifters, but extending it to other valve train components, I'm looking at some KHK valve train components on hand and find the weights as follows - lifters ~ 82 g, and IN and EX valves ~ 117 g and ~ 112 g respectively. I can't remember what you're using for valves, but when you go for the FH speed record of the universe, perhaps it might be easier and a more significant weight savings to go with titanium valves than it would be with a lifter change.
WZ507, the weight of the KHK lifters. is that with or without the adjusters please?
Also, do you happen to know the weight and possibly have a picture of the 18220-53R drilled retainers for early KR and 53KK?