Everything that everyone has said is helpful. Like you, my lower body has always been strong. A 410 squat, a 545 deadlift, but a weak 285 pound bench always irked me. I used a traditional westside barbell method for years. But then, I realized that DE days really only help guys in gear. The strength curves wearing gear versus a raw lift are different. I went from doing DE days for bench of the typical 8x3 with bands and all that shit to a 5x10 with chains. I feel the chains allow me to overload the lift and get my tendons accustomed to lifting heavier weights for longer periods. When I first started this, I couldn’t do 10 reps with 135 and 40 pounds of chain on each side.
After 5 weeks, I’m doing 150 with 40 pounds of chain on each side for 5x10. My 1RM max went from 285 to 305. I run four-week long strength cycles increasing the weight used by 10 pounds each week for three weeks and take the fourth week off to recuperate and supercompensate. This, along with perfecting setup on the bench has helped tremendously.
To sum it up, BENCH MORE!!!