I'm replacing some windows in a block wall with a brick exterior. The old windows will be completely removed and new windows installed. I was orginally planning on utilizing replacement windows without nailing fins, but wonder if there is a benefit to using a nailing fin. There is a wood buck on the block wall that has a rough opening small than the exterior brick opening. The exterior brick opening allows approx 1.5 inch on all sides. Should I utilize a window with nailing fins and then flash the nailing fin or should I flash the wood buck and use a replacement window without a nailing fin?