01-21-2016, 09:05 AM
Since you're decided, try to drill into the webs of the blocks. Drill deep enough to seat the anchors. Insert anchor and seat with the seating tool. When you whack the seating tool it is better to have the web behind the anchor so you don't blow the insert right through the thin wall of the block. That said, tapcons or even drivits would probably work for you.
Ken