Zack a welded gear is taken straight from a Toyota, the carrier is welded in several spots to turn it into a posi rear end (both wheels turn together), the welds can can have a tendency to break. The spooled gear has the carrier removed and a racing spool installed, this is the way most real race gears are used. Spooled is also lighter, lighter turning mass is better. You can expect to pay about 250.00- 350.00 for a welded gear and 350.00- 550.00+. Price will depend upon the seller and the condition. Be careful with used gears as MANY of them have not been maintained, this will result in sharp teeth on the ring or pinion. Mostly noticeable on the pinion gear. The gears will become sharp and eventually they will fail from not maintaining the "lash". I hope this helps you without confusing you. Used gears are a great savings!
