yep, skull crushers is probably my favorite tri excercise. Really builds them up, but you gotta be willing to push yourself with the weight. Especially if you want to bench a lot, because 95% of all lifters miss heavy bench presses not beacuse they couldnt get it off there chests, but because they couldnt finish the last couple inchs at the top, and thats all tricepts. Another real good excericse is weighted dips... try to do 3 sets of 8 with 100 pounds tied to your lifting belt. Fun Times