I used to use the Feathercraft rudders on boats that customers wanted rudders on. Now use SeaLect as I like the way that the rudder is pulled up rather than flipping over and hitting the deck. I assume that you have the rudder assembly with the pin. And have you done an end pour? The main thing with the Feathercraft is to get the hole straight for the pin to go into. After leveling the boat, I drilled ever increasing in size pilot holes and used a long dowel as a guide standing in the hole to see if I was getting my drill in straight. Once happy, drilled the hole slightly larger than needed, coated the hole with several coats of epoxy to seal the wood. Or you can drill even larger, seal the wood and then insert a plastic tube into which the steel pin will sit, so that abrasion would not wear on wood. To hold down the assembly a screw and washer needs to be drilled into the deck. This is where you will need a good solid base to hold it. Your wood deck will not be sufficient to hold the screw so use a good long stainless screw into the end pour for this, otherwise this screw will work free over time. And then there is the "V" bracket into which the rudder sits when in the upright position. I would make one out of wood or glue a small block to the deck into which the plastic "V" is screwed to.

I have a write up on my web site blog on the "How to" page at http://orcaboats.wordpress.com/how-to/ called installing rudder and cabling, etc., with diagrams, etc.