I just contacted FAST to verify, the injectors are indeed the same as the standard universal injector.

The critical areas are the Oring and PINTLE area, these are all identical. The actual housing maybe slightly different from Injector to Injector (due to manufacturer variances) but the injectors themselves are the same.

There are HIGH and LOW Impediance injectors availabe, perhaps thats what you were questioning. The Cut-off is at the 50# rating. The 50# and lower are HIGH IMPEDIANCE Injectors. The injectors greater than that rating are LOW IMPEDIANCE Injectors. However they ALL remain the same physical size.