You call that car modding? Please....... that's practically tacking on dealer options!
My swap involved all kinds of research, including referencing dealer service manuals, talking to the old guys at dealer parts desks, talking to other people online and in local circles who have done the swap trying to figure out what parts are needed, what's compatible, what I'm likely to find sitting around in scrap piles and what I'm NOT likely to find, and this all doesn't even take into account all the time I actually spent scouring scrap yards, craigslist, junk piles in the garage of a friend of a friend of a friend, and even being able to identify the part if it happens to be rotting away before my eyes. I cut, I drilled, I welded, I soldered, I fabricated some of my own solutions where parts were simply no longer available, and so on and so forth. I'm not even sure what year car this transmission even came out of, because it wasn't original to the car I bought it out of, it had received a similar swap.
There are no "instructions" on how to do these things, there are no "bolt on kits", it doesn't come in a box, or any of that watered down jazz. It's about figuring out HOW it works, WHAT you need, WHERE you are going to find it, and what you need to do with it just as much is it's about actually doing it!
Needless to say, the pride I feel every second of driving this car is absolutely unmeasurable and I wouldn't trade it for anything. I only hope that you and all the other hot rodders, techies, modders-of-anything, etc out there get a chance to feel the same thing about their projects, their hobby, their pride and joy whatever it may be.