Unique speedo cable?

I ran into the same situation when I needed a speedo cable for a 64 Belvedere wagon I fixed years ago. I put a later model 727 behind the 440 I dropped in it and needed a screw on connector at both ends. Carquest (R.I.P.) had a cut to fit kit that worked great. I'm doing the same kind of later trans swap to a 65 Barracuda now, and hope to find that same kit if Advance still carries it after they bought out Carquest.