DJ181
Your 5'11 and have a 35" pant insert...quite a ratio difference. (no dis on your macho-ism, but a lot of female volleyball players built like that)
Guessing your doing the old Jefferson Lift, with a BB held between the legs (over/under grip). Or is there something else you might be doing? Heavy bell= a single DB/Kettle bell? Probably time to start having more focus on the legs/quad, because if you do, you may have the advantage of increasing the muscular bwt. With the legs and the rest of the body (most notably the arms, gaining size and strength).
If training at home, and perhaps with limited equipment; as, no squat rack or PR, than might suggest the BB hack squat for the legs. Also weighted step-ups. If having a squat rack, than consider using it to it's fullest benefit. As a fair gauge, the current exercise your doing for the legs should have at least 100 more pounds on it. Unless your doing the 40-50 rep advance training thing.
Your weighted push-up is impressive. Unless your doing the push-ups on a set of blocks, which increases the ROM greatly, push-up are really akin to floor presses (most don't actually touch the chest to the floor...maybe a actually 3/4ths ROM). Might add dips (weighted) to your program, if not wanting to do regular benching. And the weighted push-up should increase greatly. (300lb floor press are somewhat average, 400lbs probably in the range of most guy's).
A 16" arm (cold measurement, taken first thing in the morning..without any added normal pump..brushing teeth, stroking the chunky monkey, etc) is fairly common for most guy's who have been training for awhile. A true 17 1/2 to 18 inch arm is not all that common, no matter with all the BS on GB or anywhere else. That is a arm devoid of fat and in excellent condition. Seem many fat guy's with big arms, but so what...just fat.
Your DB row is impressive. So that may offer a clue to how strong the rest of your body can become, including the leg power. And of course, adding muscular size. Good Luck.