I retrofit some 2004+ clamp style racks to mine last year. My main problem with the old racks was that my wakesurf board was too wide to fit in them. I bought the new racks off ebay and sold my 2003 racks individually. The 2003 racks are really hard to find, and there are probably a few people looking for a single rack. I think I came pretty close to breaking even on the whole affair.
To make the 2004 racks work, you have to cut out a large rectangle for the clamp handle to pass through and drill a hole for a screw. The picture shows one side complete with the other marked up. Working with that aluminum was not fun, and it too me a long time over the winter.
A guy on here had a pair of sampson typhoon racks for sale for $500. I think he may have sold them, but if they are still available, I would get those instead. It will save you a lot of trouble, and I would like having the swivel option. I have to remove my racks a few times every summer when we go to big on the water parties where we will be tied up with other boats with towers. I think they retail for over $1000. I don't think I'd pay that much for them.