In most situations the 5 extra spring sets in the 3-4 clutch pack are junk when removed from a 4l60e that has burned the clutch pack up.
If setup properly a new set of these springs work well in daily driver applications. If you worry about the springs being too stiff and affect clutch apply, remove one spring from each retainer. The 3-2 down shift is a bit cleaner with the springs installed
It is a good idea to reduce the height of the retainer to provide additional clearance in the clutch pack so these spring retainers do not block the pressure plates from compressing fully.
In a drag race 4l60 the 3-4 spring sets are usually left out. In most cases the builder uses a different clutch pack configuration of pressure plates and frictions, so the 5 OEM 3-4 spring setups will not function.
Dont worry how old you are... it is the mileage on your body that adds up.