you can either do 2 things. you can reduce the port area and tune it low or if you want to keep the 135sq inch port area, you would need to tune it to 40hz. tuning it to 40hz doesn't mean its gonna be too high. with your car resonant frequency, it will be lower.
box specs in the pic.
42" wide x 15" high x 28" deep.
port......13.5" tall x 10" wide x 18" deep. the tuning is a bit over 40hz.
