I do not yet have Parts Manufacturing Authority so if you choose to install these parts you will be doing so under the auspices of Owner Produced Parts.  Please carefully consider such action with your IA before you install them.  I will happily refund any purchase if you return the part unmodified in a reasonable amount of time.

The FAA recently (2012) published a good article that addresses Owner Produced Parts.  The article can be found HERE.

Also, in conjunction with the Experimental Aircraft Association, the FAA has issued an Advisory Circular that addresses part substitution for "vintage" aircraft - including our Cardinals.  The AC can be found HERE.

Finally, HERE is a letter from FAA counsel that expands upon Owner Produced Parts.  I recommend reading these documents.