I need to replace the wood keel support on my trailer. The boat is a 1988 so I assume the trailer is the same. I don't want to drive 50 miles to take a measurement. Does anyone have the measurements? What type of bolts are used? What about using a couple of treated 2 x 10's instead to the 3/4 plywood? I know I would have to raise the bunks a little. If 70% of the boat weight is on the keel, it seems that the plywood wouldn't give much support because it spans about 3 or 4 feet right under the keel with no support. Thanks for your helpMerri-Lee