If anyone is interested, this is the web write up that I used as a starting point for my ramp. I made some modifications to satisfy my mechanical engineer brain, but the ramps work great. Sometimes simple is best...
-No sideboards...didn't see the need for them.
-I placed a 2X4 across the top and bolted through them, the plywood, and the tailgate "horns"...didn't like the idea of putting that much weight on them only going through the plywood.
-I drilled one side undersized and drove a 3/8" bolt through and drilled the other side slightly oversized and used wing nuts for quick assembly/disassembly.
-I added a simple barn door handle to each half for easier handling.
I think the author makes too big a deal about the position of the truck and pulling into a ditch to load/unload...never had a need to do that...the ramps are 8 feet long, so breakover angle is manageable, even with a truck with fairly high bed height.
I also have a long bed truck, so I am able to lay the ramps down and close the tailgate.