You fabbed those? Looks like PMF gear. Hey, people say it works 
Neat link dude. That was an informative read. Appreciate it when people posts good resource links when posting.You can also take a look here, where it shows "maximum shear stress" in a chassis frame, top of page 3, left side. That colored area where the flange and web meet is where it is smart to minimize welding or holes.
Love the PMF line