I have 2 cores, both open diffs. I would really like to get a LSD unit. Buying one used is cheap, but who knows how much life they have left. The street LSD's MM has have piqued my interest, and I have 2 good-condition cores I could send in. Granted, the shipping is probably going to kill me, but still. What do people think of them? Should I just go cheap & get a used LSD & send that in with the other 2 when it goes?