Dealing with different SDKs

I have a bubble chart where I am specifying gridlines:
<mx:backgroundElements>
<mx:CartesianDataCanvas id="canvas"/>
*<mx:GridLines gridDirection="both"/>*
</mx:backgroundElements>

This is 4.13 variant, but for 3.6 it is *<mx:GridLines direction="both"/>*

Locally I am working with 4.13 but builds are still using 3.6.
Can I have a runtime switch between these two?

Thanks