Most likely it won’t make a difference, those 2 karts were manufactured real close, GP was a CRG offspring during that time. Some guys called it the blue CRG. If you notice the calipers, rotors, axle and components are the same, unless ceramic duraclan rotor brake system.
This is kind of the newer version of DR karts, but DR chassis are cheaper to buy.
Or kind of like Fernando Alonso karts and all Tony Karts/ Kosmic/ OTK stuff.
Anyhow hope that helps, if not you can always find a factory CRG spindle, but unless it doesn’t affect your handling and steering I wouldn’t worry much about it.