I'm restoring a 1949 International Harvester one ton truck. The new wood flatbed requires wood rails to sit on top of the truck frame rails. The two each 9'-0" wood rails will be made by gluing two 2" X 10" X 10' - 0" long fir boards together. Would it be a good idea to use 1/4" plywood between the boards? If so should I use mahogany plywood to add strength to the glue lam? Thank you, Gary Finch