Update! I've actually been slowly working on this scooter for the past few months, just not a lot of progress, but today, done!
Most of my time was spent building the battery pack. I had chosen samsung 30Qs, which can handle 15-20A of discharge. The problem is that a 7mmx0.15mm nickel strip can only handle about 3A. So after much research and testing, I decided to use 12AWG copper wire to act as my series connections between cells rather than trying to layer 6 0.15mm nickel strips. My 20s6p samsung pack can now legitimately handle 100A of continuous discharge.
I had to do a lot of creative parts bin scrounging from china. The base scooter I originally got from craigslist was too small to house the LR big block. More accurately, the rear frame was too small. So as I've posted earlier, I had to buy the rear frame that EG's scooter has. The problem was, upon receipt, the frame was too wide, so I had to buy spacers and 15mm bolt and grind and customize to get the rear frame to properly fit.
A good friend welded together the motor mount, in red that you can see in the picture.
The chain is 219, as recommended by EG and was easy to shorten using a 219 chain breaker from ebay. I custom designed and 3d-printed the chain guards to ensure the chain stays on.
As you can see, I had no space to for the controller inside, so I mounted outside. Its a kelly KBS 130a.
As for the LR big block. Holy balls. I took it for a spin today. I almost got thrown on my ass from the huge and instant torque. I actually can't give it more than 30% throttle at any time because it will pop a wheelie and throw me on my ass, which is not fun at 50mph or even at 15mph for that matter. I used to have a Yamaha R6 supersport and this scooter is more scary! I don't ever say this, but this motor might actually be too much, lol. The torque is so instant I have to REALLY feather the throttle. Its currently geared to hit 50mph, but I may have to gear it to hit 60 or even 70 so the throttle is actually more usable.
A big thanks to ElectricGod, who as you can see from this thread, has generously given his knowledge and experience, upon which this scooter was built. And Mike's ridiculously overpowered motor, and other's who have helped answer my questions.
I plan to add some more cosmetic details, such as tail lights, headlights and horn, and have my friend weld a cargo platform on the rear frame.