I finished one motor and pinion and this is a run through on how to install a 1/8″ (3.17mm) bore pinion on to the 2.3mm motor shaft of a 380 brushed motor. The pinion gear is RC4WD brand 12t, 32p, long steel pinion gear. Different, shorter set screws will be required (M3 x 0.5 x 3mm). I chose stainless steel set screws. 32 pitch pinions for 2.3mm bore motor shafts are very hard to find and you would probably have to have it custom made if you don’t want to adapt a 1/8″ (3.17mm) bore pinion. Pinion height is important to align the pinion correctly to the gearbox. I measured from the top of the pinion to the front cover of the original pinion and motor mount which is approximately a 66.9 – 67mm distance. I mistakenly said 70mm but approximately 67mm is actually correct. The 1/8″ to 3/32″ (2.4mm) adapter bushing is NWSL brand (osorail.com), part number 10162-9. If you decide to go brushless, most brushless motors already have a 1/8″ shaft. I do not want to go brushless. I simply want a bump up in motor performance and want to use steel pinions. Actually, most of these buggies originally utilize mabuchi 380 motors with a 12 tooth pinion gear, however, some buggies out there utilize mabuchi 390 motors with 10 tooth pinion gears which I believe is for more torque when the buggy comes with the larger type tires. I do not believe that 380′s and 390′s are interchangeable, however, I have not verified it. Thank you for watching.