5+ means 5,or more. Ive been running 5/3/1 for a while now and what I can say is you would be better served underestimating your training max, and working up, insted of overestimating and hitting a wall. If i were you I would make my training max 360 and start from there. Rember also you dont allways have to push the last set over, especially when the weight dosnt warrant it.