I did see the video of that 8.8 swap.
8 3/4 are harder to find here and the few I’ve found range from $1000 for a narrowed one and 2k for another one that’s been built.
8.8 might be the way to go.
Figured the 7 1/4 might live behind the 318 for a while as my daily since some v8 cars came with it.