I believe i figured out why they used it. I was able to get ahold of the guy i bought it from which is tough because he speaks mostly Spanish (i had to drive to the Mexican border just to pick this car up). He said they put the s10 rear end in here to get the rear disc breaks and also for the LSD which i believe is called posi track for these rear ends. They did add a brake distribution block and an aftermarket universal master cylinder.