TT did make a kit for the 24v they just never made a basic cut down version of the kit. A cut down version would have been good for around 350bhp but would have been in the region of 5k and as your average granada owner isn't into modding cars and sticking 24v's into xr4x4 wasn't really common 5 years TT didn't bother.

To get a 24v's to sustain revs above 6.5k you need to add a ladder frame to the bottom, but 11+k