I have the 440 source flywheel and a Mcleod 130 tooth flywheel and if you put them side by side they look identical, you can take the balance weight from the 440 source wheel and bolt it to the Mcleod wheel and vice-versa. The balance weight from 440 source seems a little big, its probably close enough that it wont hurt anything but the weights that Mcleod sells seem more accurate. The Mcleod wheel is SFI approved where as the 440 source wheel isn't so I guess that's why it's 1/3 the price. I think if 440 source flywheels were blowing up and cutting peoples feet off, slicing cars in half, etc.. you'd see it all over the internet and as far as I know that's not the case, I haven't seen any negative press anywhere about them.
