There is a bit of a gap between the end of the seat rest and the wall, I'm 6 ft 1, and I'd normally assume on more than 3 inches (why am I not using metric) from my heel to the bulkhead. At OLCI you can go for 64A perhaps, or call up for it, which has a bit more space. I would be ok to stick with 64K in your circumstances but grab 64A if you can.