I installed the front Biltein shocks a couple of days ago at 17500 km/10937m. They are installed at the lowest clip (stock height) and there is no noticeable change in the front end height.
I removed the front strut package at home but when I tried to compress the springs with two econo spring compressors it didn't look good so I took the struts to a front end place and they changed the Ranchos with the Biltein. I installed the front struts at home.
After a 80km/50m drive this morning on our asphalt roads, the truck now has a stiffer ride (more jar when crossing the breaks in the pavement). I will be towing the same trailer towards the weekend and will update if something is different.
IMO and FWIW if your Ranchos are still good, run them until they need to be replaced. I don't feel the change was worth it for me. I drive asphalt 2 and 4 lane highways that have lots of pavement cracks and later on they grow with the frost heaves.