The spicers will not be drilled through the cross, so you will have to drill each cap individually... I don't know about you but I don't think I want 4 grease nipples spinning around on my front axle shaft. There is a good chance they will get knocked off by sticks and crap. Then with nothing in the hole, you will get contamination from water and dirt.
Also if it is the forged Spicer, they come with instructions saying not to mix caps with cross locations and also not to add any grease as they have exactly what is required in each cap.
Cheap Thrills Off Road
Member of Team FSU!!!