Just swapped over to 4.56 gears with a new posi. The factory M80 I mean G80 was about to grenade (see pics) so I needed to replace it. A buddy of mine works for a Dodge dealership and hooked me up on a new posi from Dodge. Swapped over perfectly and the new gears were exactly what I needed to get my rig back to Road Rocket status! Special thanks to Steve at A-1 Differential for doing a great job on the gear swap!