I book marked your installation a while back and have read it over many times because you did an excellent write up. I think its likely forward area of my tunnel will need to be enlarged. I think the tunnel rear off my cross member I am good there.
I am working on indexing the bell housing to engine while engine is out of the car. After that I will get engine in with trans bolted up and see what is needed to get that required minimum 1/4 inch clearance between trans and trans tunnel. I won't be surprised if I have to do a lot more cutting welding to get the trans to clear the tunnel.
My initial cuts were based on ToddRon installation instructions: