I plan to use 3/8" thick x 3" wide A36 steel flat bar to connect between the LVL frame and the aluminum extrusion. The steel bar would be epoxied to the wood frame. Would some kind of fastener necessary? The aluminum extrusion rails will be bolted down, through the epoxy and the steel bar, into the wood frame. The highlighted area (darker blue) will be leveled with precision cast epoxy.