Perhaps the T18 is listed as a TE72? Whatever, repco have no #$%^&* idea usually.
Can't comment on the TA22 slave, however just went out and measured mine up (with T18 slave which is not relevant).
Damn cold out tonight.
From the front surface of the outermost end of the clutch fork arm to the face of the bellhousing (where it meets the engine plate) is 100mm.
An alternative measurement is 46mm from the same spot on the clutch fork to the centre of the rear slave mount bolt.
Clearly you need to ascertain if the clutch fork is positioned correctly behind the bearing carrier which these measurements should answer, otherwise you will have to pull the box back out......
Good luck!