You would use the same Tamiya hinge pins, should not be any drilling required. You have to shave material off the Xray C-hub if you want it fitted to 418 arms.
I went from an X-Ray T4 '13 to TRF418. The 418 is an immediately better handling car, even on lower traction asphalt. One of the things I noticed is maybe this is attributed to how much less unsprung weight there is compared to an X-ray. All the X-ray suspension parts are beefy, but they weigh a lot too compared to the BD7/418 counterpart. I plan to stick with Tamiya parts on my car.
Isn't the diameter of the Tamiya hinge pin smaller than the hole in the X-ray chub? And I agree, the 418 is a significanly better handling car.