Dam it! I see where in one way you use the multiplier of 8 and another 5? If I used 5 I would have guessed 40t! I guessed 3" diameter so 3 x 3 = 9 x 8 =72t! 3 x 3 = 9 x 5 = 40t!
Why is there two different multipliers? Anyone know? Bren will send you another shirt if ya do!