Interesting oil filter adapter positioning. I have not seen it done that way before.
Just a bystander question about the stock starter. Will you be able to get it out fairly easily after the motor is in the car? In the picture it looks very close to the pipes and also possibly subject heat soak issues. I had headers on my 260 for many years. Even with a heat shield blanket it would not always start (turn over) right away after the motor was good and hot. Had to replace the starter numerous times over the years, sometimes just to replace the bendix drive. Have you considered one of the smaller, gear reduction starters if that would make a difference removal and heat soak wise? Might need the additional power anyway with a high compression motor. Again, just some friendly bystander thoughts.
Regardless, looks like you are doing some major pioneering, and I am sure rewarding work here!
Gene