Well, to be honest checking runout in the cases has little to no value. The cases help hold the crank in alignment to a small degree while bolted up. If the runout is not in spec once the cases are forced closed "bolted down" it will lock the crank in place with "no movement". Now, checking run out on v blocks will show runout before the crank is installed. A regular dial indicator with base will suffice. The video probably shows hitting on the crank web which will cause the web to move on the pin to align.
You can grab a cheap dial indicator from Amazon or eBay with the base fairly cheap.