Anyone know what speedo cable or other adaptor gizmo's I might need to marry these two willing partners?
May I suggest Speedometer Service Co. in Colorado Springs. He made an adapter cable for me to mate the existing cable I had coming off of a Saginaw to an old S/W Wings speedo that worked great. He is very reasonable & fast...sent the thing out before I could even send him the money. I think his name is Rusty, but I forget his HAMB name...phone is 719-632-3165.
Have you tried screwing the stock '33 cable to the trans yet? I bet it fits perfectly. Many of the later GM transmissions have the same fitting as the early Fords.