I managed to get GTO master cylinder fitted with its cup sticking out on the other side of the cylinder.
Tried to use VR4 cup but it doesn't fit.
Cylinder and cup need to go separately so cylinder gets fitted first and then cup.
Cylinder need slight mod to the sticking out part which touches the chassis so i ground it down to the width seen on the picture which gives enough room.
The other thing was slightly in the way was power steering pipe so i cut the bracket down and moved hose pipe to make enough room.
Threaded pin holding the cup was replaced with long bolt and screwed in from the other side than the original pin which allows to put the cup in after fitting cylinder.