I would like to install a double-hinged exterior door to replace an existing sliding door in an eight” thick cinder block wall.  Using a standard 5’ wide door, the opening only allows space for 1x bucks and shims. 

The instructions specify that if 1x bucking is used, the jamb and hinge screws (2 per hinge) need to go into the block wall.  Every other row of the wall has a half block (due to the cut) with only 1/2 inch of material to anchor into.  

I’m looking for advice on the best way to get solid mounting points for the mounting locations that align with these blocks.  Thank you for taking the time to read this question!