Auto Racing: chevy 8.5 / 10 bolt rear end, salvage yards, cop car

Question
Mr. Mazio,
I have a 10 bolt 8.5 rear in my car right now, it was out of a 1988 caprice cop car.  My problem is it's an open rear end and I'm looking for a limited slip.  I have been told by a few guys that there is no limited slip rears that will bolt up with what I have and I just find that hard to believe.  I have looked around the net and found that 80-90 caprice wagons with towing packages have a limited slip rear but I'm not sure if they would bolt up if I found one.  Do you know if this is my only option and will it bolt up or is there anything else more common.  I've called several salvage yards and they don't have any of them anyway, I live in a small town and not a whole lot of yards in the area.  What I have is a rat rod, I use what I can afford.  It's a 1982 caprice frame with a 468 mostly stock with 1988 caprice rear end, under a 1955 chevy 210 2 dr. body.  If you have any ideas about a rear that will bolt in and work I'd sure appreciate it.
Thank you for your time,
Chris

Answer
HI CHRIS. ACTUALLY YOU HAVE A GOOD STRONG REAR NOW. THERE ARE 9 SECOND CARS RUNNING 8.5 REARS. YOURS IS EVEN BETTER THAN EARLIER VERSIONS BECAUSE GM INCRESDED THE AXLE SPLINE COUNT TO 30 ,SAME AS THE 12 BOLT. ALL YOU NEED TO DO IS INSTALL A POSI UNIT.THERE WERE 2 VERSIONS ,ONE IS FOR 2:56 AND LOWER GEARS BUT YOU CAN USE A RING GEAR SPACER TO ACCEPT GEARS THAT ARE NUMERICALLY HIGHER .THE SECOND UNIT WAS FOR 2:73 TO 5:13 GEARS. TRY TO FIND A WAGON WITH A TOW PACKAGE OPTION OR A SCRAPPED POLICE OR EMERGENCY TYPE CAR,FIRE CHIEF,RESCUE SQUAD ETC. YOU CAN CHECK THE GEAR RATIO BY SPINNING THE YOKE AND COUNTING THE NUMBER OF TURNS WHILE WATCHING THE TIRE MAKE EXACTLY ONE ROTATION.3.5 ON THE YOKE TO TURN ON THE TIRE IS 3:42.IF YOU ARE OK WITH YOUR RATIO THEN JUST TAKE THE POSI . YOU CAN JUST SWAP OUT THE OPEN UNIT AFTER BOLTING ON YOUR ORIGINAL RING GEAR ,JUST REMEMBER THE RING GEAR BOLTS ARE LEFT HAND THREAD.YOU CAN FIND SOME CHEAP POSI UNITS ON EBAY TOO ,MAKE SURE THEY GUARANTEE ANY USED ONES BECAUSE THE OEM UNITS ARE AUBURN SCREW TYPE  THAT CAN BE WORN  WHICH THEN THEY AS GOOD AS THE OPEN UNIT AND THEY ARE NOT REBUILDABLE ,A CLUTCH TYPE WOULD BE THE BEST ,LOOK AT >http://shop.ebay.com/?_from=R40&_trksid=m570&_nkw=8.5+POSI+&_sacat=See-All-Categories
GOOD LUCK  CHRIS