SW gen 2 engine into gen 1

[Redd]

Hey
I'm putting my gen 2 SW20 3sgte into flying bricks old SW20 and was wondering what parts are different engine/gearbox wise. Tex has filled me in on a few things (speedo cable, different fuel and vacuum lines) but just want to know if anyone has anything else to add. Does anything need to be modified? Also I had just bought a Greddy Speed limit remover before my crash but hadn't installed it and I was just wondering if it won't work with the speedo cable as apossed to the electric stuff in the gen 2.
Cheers
Genga