slip yoke question
 

I have a 27 inch spline slip yoke. One of the spline is blind (not there).
My question pertains to ordering a new one. I contacted dennysdriveshafts.com and it seemed the salesman wasn't sure if I would be placing the right order based on what I was describing.
My transmission is a 70's saginaw chevy 3 speed transmission bolted behind an inline six. The slip yoke looks exactly like a 1350 series Spicer yoke as pictured and described at dennys. The salesman thought it might take a 1330 series. He also mentioned that the looks may not be the same anymore. The prob I have is that the 1350 has a very distinct crescent carving at the bottom curve in the yoke. If I were grabbing one off the shelf, that's the one I'd pick.

Here's the simpler question, do I have the correct yoke? The denny's ad says my yoke is for the Muncie line up M20, etc. I have a Saginaw. The current yoke slides in the tail of trans without a hitch (that I know of).

I realize this is a left field question. Just hope a couple of you can respond.