Very late reply. Just having a look through the information on these cars as I prepare to put two GTA Turbos back on the road.
The Anti Rattle Bush kit used in R12, 16, 17 etc (Part No. 7701455252) fits the GTA rack although the GTA Parts book does not show it even being there. I have fitted one to a GTA with the rack in place. After removing the passenger side tie rod, then the circlip and washer I have screwed self tapping screws between the bush and the rack, and then turned the steering to push the bush out. I have done this on many Renaults without damaging the hardened steel of the rack.
The bush kits are available in many shops quite inexpensively, being only 6 Euro plus freight from Melun Retro Passion.
https://www.melun-retro-passion.com/gb/ ... 5-r17.html