020 gearbox swop?

Hello need some help,i have a 83 mk1 diesel with a 4 speed 020 box,i have brought a 5 speed 020 box from a 97 golf diesel hoping to swap it,looks identical,cable operated clutch,linkages look the same,but the speedo drive is electronic,have took it out and looked inside,looks the same from memory but can i stick my mk1 speedo cable in the hole and it will work??? the electronic thing has a plastic gear on it like a cable,also what about the gear linkages on the car,do i need to change any of the rods?
Good luck with that lot
Please help dont want to fit it and have no speedo!
Lee
1994 citigolf x2
83 mk1 diesel
83 mk1 GX
02  passat pd tdi 130
 :read:

I have done this myself only in reverse, I fitted a few electronic speedo drives (speed sensors) into a cable operated box and they work a treat so I would assume its the same principal in reverse.  8)