valve stem thread length too short

The length of the tire stem valve on the main gear of my LS-3 is too short for the fill valve from my compressor to open it. The tire hub prevents the fill valve from pressing down far enough to open the stem valve. The short stem valve appears by design so it can clear the landing gear linkages as the tire rotates and not get sheared off. I tried using a valve extender but again, the length of the exposed stem valve threads is too short for the extender to screw down far enough to open the valve. Does anyone have this problem and was able to solve it?