they are both the same taper- 13 dictates the taper- a 14 would be steeper and give more of a "hit" the 68 and 70 part dictates the diameter of the straight portion- 70 is wider and thus leaner from 1/8-1/4 throttle.
the MS/NS part is the length of the straight portion but they are pretty similar i think and this can be adjusted with the clip.
go to www.carbparts.com and you can convert these needles into the "XYZ" needle codes you can buy these needles cheap
seems that the 70 is a lean needle, i might have a leaky rightside crankseal. runs rich when cranking on the throttle. went from a 175m to 170, 55 pilot to 52. and my stock needle (r1370n) is at 1st groove, AS is 1-1/4 out. thanks for responding.