by the time you rebuild or replace a couple of rb20 gearboxes you would have paid for a strong rb25 gear box. you dont need to change the master cylinder and the slave cylinder will generally come with the gearbox, as old mate mentioned, an auto crossmember fits perfectly in a cefiro, your clutch will fit, make sure you get a push type gearbox out of a series one r33, just get some one to join the rear of your drive shaft with the front of a r33 front drive shaft, next is the speedo drive, nissan navara speedo drive tuned upside down with a r33 gear on it, not that hard really. factor in selling your rb20 gearbox when it is not smashed and the tow truck to pick you up after you are left stranded some where with a blown gear box and the answer is simple really,