To summarise, my car came stripped with some known bits missing and probably more unknown missing.

Following yesterdays work i can now physically fit the engine & box. I need to do this aswell as i am running out of space to store & work around. My engine is built up except for the carbs & coil. Can these be fitted afterwards, even if it is a little awkward.? The engine lid is in one of my lofts so i have more space from up top to access the engine bay.

It's actually easier to install the engine with the carbs off. Just tape off the manifolds so nothing falls in.

Install engine w/o carbs for sure. But do a bench install of them and get the linkage issues worked out prior to installation of the engine in the car. Easier to work on the linkage when it's right in front of you. Make sure it's free and no binding. Add return spring and ensure throttles close. Also do your best to synchronize the carbs by eye - that is are they both closing together. Saves time and your back.

Doing this today. Powerplant install tomorrow with carbs removed.

Click to view attachment

Depends on how you're installing it, jack stands and jack for sure carbs off.

For those of us lucky enough to have a car lift and some kind of table or lift table, carbs on works well. You just have to take care with the sides of the carbs as it goes in.
A six with carbs is easier than a /4.