If it's s soft-rate (non-race) lowering spring -and- FRESH (low miles) stock dampers (shocks and struts) then yes, it's okay BUT NOT FOR VERY LONG. Eventually, one will need a better damper to control the energy that the weight of the car feeds into the spring.
For example, I ran a 10,000 miles set of SVT Focus dampers with H&R's Sport springs for another 15,000 miles and as that 25,000 mile mark approached I could see where the damping was getting to be a little "thin"...
SVT Focus dampers are far better in "valving" than ZX3 units. H&R Special Springs suggests that stock dampers can be used with their Sport and O.E. Sport springs. I say that that's true, but not for any serious performance driving, and definately not for longer than 25,000 - 30,000 miles.
I'm now running the KYB AGX adjustable dampers with my H&R Sport springs. The car is far more "focused" and much better damped. By the time I accumilate a total of roughly 25,000 miles on these AGXs, however, I'm buying Konis or GAZ. Call it research.
:banana:
It's always been an industry standard, more or less, to replace OE-style shocks and struts at or near 40,000 miles; fine for the no-performance driver going to work in fair weather, but for anything else, I feel that that mileage interval is too far. If one wants the best-handling Focus one can have given the hardware one has selected and installed, stay on top of the dampers - go for 25,000 miles replacement intervals (unless one already has some uber-quality adjustables that cost a fortune when new...)