Does anyone know if the inside of the fuel-tank of a 750/906 Paso is the same as the one used on a 907IE, this because of the use of injection instead of carbs........

The 907 Tank has inside the Holder for the Pump + Filter.
Part Number is 58610051BA (Red) or 58610051BB (Black)
The Paso 750 is 037083253

And it looks that the the Fuel exit is on different positions , and the 907 has 2 (outgoing + Return)

I say they are much different

As mentioned the internals are different as the P750/906 tank doesn`t have any.
It still may be possible to use one on a 907ie if you use an external fuel pump and fuel filter like on the P750/906. The tank has a return line so this wouldn`t be an issue. Fuel lines may need a different routing and you would need to find a place to mount pump and filter.
I don`t know if anyone has done this yet. I`d try to find a 907ie tank and if you can`t or they are too expensive I`d consider a P750/906 tank and the required modifications.
The bottom side of the tank, meaning the area of the airbox should be identical.

G.

it all depends where you live, here in Aus external uninsulated fuel lines are subject to hot temperatures and fuel vaporization can cause havoc during hot days at low speed, in this case its better to leave most FI parts inside tank submerged in cooler petrol