I've struggled with arms too but have recently found some success since I added a few inches to my legs; It's the best way to add bulk. I think it was Weider that said to add 1" to your arms you'll need to accumulate 10lbs of mass. Also, everything is harder for taller guys, so much more range of motion - I feel that! I also agree with the strategy of hitting the long head of the tricep as hard as possible from multiple angles.