I'm not aware of the thread size on the oil feed section of the GT30 CHRA but the GFD oil feed line thread size is M11 x 1.0mm (I'm pretty sure)
Also, the GFD line is -AN3 which would be perfect for GT30s (if it fits).
The water line thread size on the kit offered by GFD should be M14 x 1.5mm. Time to look up what the GT30 CHRA has for water and oil thread sizes (to make sure).