28 or 30 spline?

[MTPockets]

i am still putting my truck back together from last weekends mud run. i found a knuckle for nothing, but the axles are killing me. a local shop had some 10 bolts laying around and they told me i could grab the axle i needed.
the first one had no hubs or rotors, so i went for it first. turned out they were thicker for a 3/4 ton 10 bolt.
next i went for the 1/2 ton 10 bolt, wrong spline count! it was 30 instead of 28.
i will go back monday and try again. i have a set of spares coming from a fellow ck5er, but i was hoping to get her going this weekend.
WHEN DID THE SPLINE COUNT CHANGE?
thanx,
MTPockets.

 

[CK5]

1989 was the first year for 30 spline in the 10-bolts. And all Dana 44's were 30 spline.

5,000 Pounds of American Rolling Steel

 

[90K5]

89 was the first year for 30, but some still had 28 in later years for some reason.

90K5