I have to mount a 10′ x 8′ retractable awning to the side wall of my house.  The house has cedar clapboard, 1/2″ plywood sheathing and the attachment area is a cantilevered wall so there is a 2″ X 10″ header in the attachment area.  I will attach (2)  2″ X 6″ mounting blocks to the wall and then attach the (2) metal awning brackets on the mounting blocks.
Option #1:  Attach each mounting block to wall with 4″  structural screws…4 screws per block.  Attach each awning bracket to mounting block with 4″ structural screws or 3/8″ lag screws…2 screws per bracket.  The rim joist/ header penetration wil be 1  1/8″ to 1  1/4″.
Option #2: Pre-attach each awning bracket to mounting block with 3/8″ carriage bolts…2 bolts per bracket.  Attach each mounting block to wall with 4″ structural screws….4 screws per block.  The rim joist/ header penetration wil be 1  1/8″ to 1  1/4″.
The awning weighs about 40 pounds.
Does anybody have a preferred option?  I was originally all set to use option #1 but then figured that option #2 may make it easier to get the awning brackets level with each other.  The brackets will be about 9 feet apart.  I have a long pole or will use a string level.