This Chassis fits the body of Scaleauto Porsche 911 991 GT3 RSR. For example SC-6066R and all other which are identical in construction. This chassis is made for use on Carrera Univeral 132 tracks. You can use the slot.it motor mounts (anglewinder,. sidewinder and inliner) as well as the slottolution motor mounts (inliner for 13D, 18D and Sideways Inliner).
The cockpit needs no modification if you use slot.it/Scaleauto sidewinder or anglewinder.
If you want to use the Bühler, Johnson or Motraxx X283 motor you have to modify the cockpit or use the printed slottolution cockpit, which you can find here as single part:
..and here as a kit with chassis: