^^ I was wondering the same thing... is the sheet rock fastened to the concrete wall or is there furring strips? You will be safe with tapcons, use 4-6 per cabinet at least, there will be a lot of sheer pressure once the cabinets are loaded.
I am not sure how the sheet rock is fastened, our contractor did it while I was staying in the RV. North 6' is concrete block and south 6' is stick frame. I could not see the transition after they hung & mudded. Dear husband thinks 22 nail gun. Something about gun powder...?
I would guess there is furring strips, and they used a power nailer (blank gun charges) to attached to block wall.
Yep, that's from a power nailer... word of advise, don't hit one of the blanks with a hammer after a misfire... loud, very loud.