Only down side is you won't be able to install a fully assembled dash into the car because that would prevent access to the bolts coming up from the bottom. So its a trade off.
1/4" drive with a circus of wobblies/extensions should do it.
What is going to be in the way? heater hoses? seems like most of it is just a jungle of movable objects. Maybe the windshield wiper assemblies? Not trying to be smart here, I am really wondering if its worth it. I can still turn back.
