I am insulating my garage. In the corner there are 2 2x4's that form a "L". There is only 1/4" between the 2x4's and there is a 3 1/2" by 3 1/2" void behind them. I think spray expansion foam is the way to insulate that but I am not sure if I should use the maximum or the minimal expansion foam.

Is this the way to go AND if so should I use Max or Min expansion. Don't want to blow the wall out!!