My T9 and T5 were the same dimensions. Apart from a bit of a shifter difference of maybe 3/4 of an inch to the left for the T5 they are the same size really.

The bellhousing on a T9 bolts internally. In other words you MUST remove the bellhousing from the engine to remove the gearbox. The T5 bellhousing bolts externally so that you can remove the gearbox from the car with four bolts, leaving the bell housing in place. Must faster, lighter and easier in my books.

Speedo cables are not the same.

The external dimensions that concern you will be in the "belly" so that the bulk of the gearcase will be a bit wider. where will it be "close" for you? Width? Height? Length?