A518 Questions

I have a few questions if you could provide links to parts I might need that would be helpful
So I'm putting a 6.1 in my 68 Cuda I have the HDK frontend and the engine. The body work is almost done so I don't want to cut the floor up for the 545RFE. I would really like overdrive and found a good deal on a built 518
My questions are
Does the cheetah 727 shifter work on the 518?
Do I need a special lock up convertor or spacer?
What do I need to make the overdrive work?
Will the 727 crossmember work?
Can I buy a drive shaft or do I have to get one made? I have a stage s60 with 4.10

Please be patient with me this is my first car build ever