I have a 93' 240SX S13, ive currently had some probles with my car, one being that the crank pulley came apart while driving

, what fun, haha i still have 2 of the 3 stock pulleys attached, but the one i need is gone, my questions is, Do the underdrive pulleys that you can buy on ebay help? should i go stock, or get the upgrade, the pulley imlooking at is 45+ Shipping, the Stock pulley is 301+Tax, what process goes on with swapping this pulley out, its splined so i figure its not pressed, just remove belts, back off the locking nut, and swap them out? well thank for your help i appriciate every letter you guys write