So, I have been gifted a 91 Gonad... er Nomad.
Decent beast for the price, ($0) going to use it as a general run around for my start up business.

But....
Runs rough, and a quick check shows the carbie is loose. Not to the manifold, but the upper body is loose to the lower. The bolts are inside the carbie, so it needs to come off.

How do you remove the stinking thing when it's in the vehicle? you can't even see one of the nuts let alone get a spanner to it.

Do you remove the manifold? And the attendant cooling hoses.

Any one with an easier way?

Have you taken the airfilter off and tried to tighten the screws that hold the top onto the bottom which should be accessible from the top?
If you want to remove the whole carby use a cheap 12mm? open end spanner and bend it in a vice like a banana.
Should reach those hidden nuts.
If still no success, take the whole inlet manifold off...

It's not the top screws, Nick. It's the screws that affix the carbie body to the base, from the bottom and internal.

A cheap spanner is a good idea, but you can't even see one of the nuts.

Manifold off is the only option (apart from engine out)

Blood "cab over" designs without a lifting cab.

The answer.

The two inner studs/nuts are though bolts that come up from below.
Allegedly so that you can remove the carbie from the manifold.

Yeah, good luck with that. Entire manifold off is the only real answer.

Why a carbie would be assembled without the use of loctite or other thread locker on it's internal screws is beyond me, but Nissan chose to do just that.