Well you really should be using the flyback board WITH resistors. It's not an OR.
The new method is the LowZ extension board. True peak hold driving of the injectors. No resistors needed.
I'm running it on my VEMS'd whiteblocked 240. Works like a charm. (750cc injectors)
http://shop.vems.hu/catalog/lowz-extension-channel-p-161.html