How much work to write a rb25det into a 62 ford falcon?

Have been messing around with what to do with my falcon, I thought about an ls, normal 302 or sticking stock 200inline 6 with I believe upgraded camshaft and crank and just putting 20 psi in boost on it. Or try to do a rb25det swap, I know it's a lot of work, would it be just just like a normal ls swap? Or would I literally have to rewire everything and get rid of the old wire harness, I didn't know if there was a way to connect the two.

Yes

I'm pretty sure you would be the first to do this swap. A 289/302/351 has been done and probably lots of how-to on the internet, but a Nissan engine not so much.