Total spline 2.28?

[cgbemis]

So I'm talking to this guy about buying a bunch of misc. T-Case parts. I see a picture of the parts he's selling, and lo and behold, I see an input shaft that has splines that look like Marlins Total spline set-up. The input doesn't neck down like a normal input, but rather the splines run till just about the bearing. I know this isn't a 4.7 gear set, as the gear on the input is too large. So what is it? Oh, and it's 21 spline.

[kyle_22r]

probably an input from an early 4 speed truck.  however, the splines "neck up" instead of having a relief area, so you need to grind them down to use it in a later transmission.  that could be why it's like that

[Marlin]

All 79-80 20R 4 speed [side shifting L43 transmissions] had a 21 "total spline" input that necks up [thanks kyle-22r] due in part to the short trans output coupler that does not have a relief to aid in trans to t-case alignment.
Since these gears were not "quiet run", the helical teeth are about 1/8" narrower and therefore will not properly work with a May of 84' and newer gear set.
I have seen this input shear off at the recess on the input spline just before it gets larger

Marlin

[cgbemis]

Cool Marlin, thanks.