I happen to be doing some reading recently on (ferrari, datsun L6 motors etc) v12s and L6s and angle of crankshafts etc. I came across some info on why v12s and L6 motors are "naturally balanced". Apparently aside from crankshaft angles uses of flat plane crankshafts, one of the biggest factors was the firing order of the engines and how that then affects the throw of each cylinder balance the other piston throws (in basic terms).
So - that being said, theoretically, what firing order would a sbc need to have to be balance like these motors?
on a side note