4 greys are safer as well if for some reason you loose the function of one of the grey injectors then the cylinder gets NO fuel and it wont really do any dammage. but if your running 2 greens per cylinder and one crokes it the cylinder is still getting fuel but only half what it needs hence... runs lean and bang!

mapping is sooooooo much more advanced now to what it was when the 8 injector plenumns where designed so there really is no need to use them.

be sensible. use 4 greys!