gb from the silvias should be good enough if you do not intend to go full insane 700hp off that engine.

more robust axle, driveshaft, arms are needed to accompany. my friends planned to use a navara rear axle for his KE, maybe you can start sourcing diameter and measurement for axle from robust vehicle.

ofcourse, chassis strengthening is most important when you wanna do things that were not suppose to do on a car, especially old car with beat up chassis. cars are not suppose to drift anyway. full set of Ultra racing bars, or better yet, you can contact UR for full roll cage customization quotation.

go join more car clubs to gather information. modifying and customizing will be pain in the ass and your car will stay in the garage for a very long time.