Man glad to see someone is making progress! Im sure not!!! LOL
I think you'll be happier in the end with the small block. I've always kinda wondered why alot of people a lured to the BB. Lotsa weight ya know. I know that was a freebee and that helps to push it into the picture!
I see the steering is going to be tight. Are you able to run the shaft between the header and the block?
If so, maybe a system like what was used in aircraft a long time ago, would work for you to transfer the drive down the fire wall. Ill see if I can find a picture. Many guys have started using the method Im referring to, on Rat Rods.
Also, since you will need to service the engine at some point, have you thought about a removable fire wall? Or maybe a removable tunnel, sorta like a van. If you do something like a "fake" fire wall, you could conceal all electrics, as well as any mechanical "guts" of the steering.
I probably havent come across very clear. Ill try to post up some pics.