HELP ID 9IN

[RICK]

I've been collecting and stashing away all kinds of hot rod parts for so long, that now that its time to use them,,,,,I can't remember where I even got them from.  [oldtimers?]
  With 4 months before SPEEDWEEK, I'm nowhere near ready and need to make every turn of the bolt count. I dug these two different 'posi' units out, but don't know which to use? Can anybody look at these, and tell me what I've got. Which one/type is better/stronger?
 Both are 'POSI' and both are 31 spline.
  The one on the left has semi-counter sunk ring gear bolts. I can't really get a socket on the bolt?
 It also has 2 phillip head bolts holding it together
 the one on the right has 3 straight screw head bolts holding it together, and seems to have a 'machined' surface on the ring gear side [more than the one on the left]


 thanks    RICK

[russ jensen]

Can't rember which is which  either ; doesn't really matter however, had one in my rod might as well have open gears, got so fead up with it I put in my lawnmower and it isn't much of a posi there either. replace w/ 12 bolt which is a real posi setup.

[russ jensen]

Just a P.S  you have put so much effort into your rear housing , a gleason dual drive instead of posi unit would finish it off in grand style [if still avaible]. These units devide up power to wheel that needs it most and less to one that doesn't, wear out quite fast but you won't see hours of use like stock car.

[EVLEE]

The Gleason really sees more hours in race cars at The 24 hrs of Daytona.I have worked on more than a hand full of cars that had them and they are GREAT!!
  I will send this on to my brother and ask him He has been running and buying and selling 9" Ford rear ends for over 30 years.
                     Lee

[EVLEE]

Rick
 My brother and his son both say to use this (so called 4 pin spool) on the left in your pics!!
              Lee