Well, your arm strength is definately out of balance. The triceps are approximately 2/3 of the muscle mass in the upper arms, and should be proportionately stronger than the biceps. Yes, this also results in a decreased BP. At some point in the BP movement, depending on your bone lengths, etc, the triceps take over from the chest and shoulders to finish the movement, therefore stronger triceps will result in a bigger bench. The upshot of this, is that with regular training, paying attention to your triceps, you can easily bring them up to par. I'd stick with basic movements though, and since your interested in benching, close grips (don't go too narrow) at about shoulder widthwithj your arms in close to the body will do the trick nicely. Lead off with regular benches or overheads, and follow on with some closegrips and/or some skull crushers.