Help? Problem: Speedometer cable for 727 transmission/65 Cuda

Hi guys, I am upgrading my entire powertrain and I now have a new 360 block with a brand new 727 transmission from Performance Automatic. I am now faced with yet another interesting problem. The old speedometer housing connector that goes into the side of the new 727 trans is about 1" in diameter (the old cable came from the original 904 trans). Problem..the hole in the new trans is about 2"..so the cable/housing is too small!

So...any suggestions of what to do? Is there someone that makes an adapter? Or do I need a whole new cable (because the old cable and old housing appear to be one solid unit that can't be separated). IF you think I need a new cable...do you know where I can find one (I have already called Performance Automatic, Jeggs and Summit...no luck). I am guessing I might need a used one out of a mid 70's MOPAR. The next question would be...even If i could find the correct cable that fit into the housing of the 727, would the other end match up to the insert of my current original factory speedometer? (Again I have a 65 Cuda with the original gauge cluster). Or...do you think I will need to change out my old gauges for a newer more modern cluster/cable/speedometer? By the way..I know the speedo gear is based on the gear ratio and tire size. I have a new Dana 60 with 3.54 gears, and 225/70/14 tires.

I have attached some pictures...Ok Guys thanks in advance...show me your MOPAR awesomeness and help me figure out a solution PLEASE!