Googling around as you do I initially found the story of Mark Kirby’s newly engineered Flathead V8 block on the Coker Tyres website
This is a quite old story from back in 2010
This page led to me to the Motor City Speed Equipment Website
Here you can find some details and specifcations for the newly engineered flathead block, not sure how old this information is?
There is also an old article here on Hot Rod Network
I also found a video on YouTube from 2012 showing Mark discussing the project
I’m not sure what has happened to the project since but some chatter on the H.A.M.B suggests that Jon Hall on Shadow Rods may be involved?