Rear dif question?????

[broke_okie]

I have a slight problem and want to know if anyone can shed some light on the subject. I bought a detroit locker today for my 1971 F100 4x4 . I ordered the part recvd it and took it to a shop to have it installed and they told me that my rear end was not a Ford 9" that it was a 9 and 3/8" ....I have never heard of this,they told me that you could tell by the curl in the ribs on the third member and the pinion support was larger than a 9". It has a factory limited slip in it that does not function. They also told me nobody makes a locker for this rearend.Know my question is ...is the information they are giving me true? Is there a 9 3/8 " rear end and if so does anyone make a locker for it? I am trying to decide whether or not to just go find a 9" 3.50 gears and 31 splines to have the detroit put in or buy the correct locker for the 93/8" if one is made. Thanks all.....

[heep70]

I haven't ever heard of that.

What about an 8.8"? The offered 9.75 in 1999.

[heep70]

Check this out. This from a site I found. The link is below.

"Here is something else you may run across, a 9 3/8" ring gear housing(sometimes called a 9 1/2" Ford carrier),I don't know much about them, but looking in the book they appear to have come in the larger Lincoln and Mercury vehicles.Note casting number C8AW-4668-B on pinion support and the double ribs(spaced further apart) with the end bent down on one.From what I understand most parts from these rears do not interchange with the 9 inch carriers.I have heard they can be installed in a 9" housing if the housing is notched for the wider gear and the gasket for the 9 3/8" is used (bolt pattern is supposedly the same).I have started to see a few of these in some Ford pickup applications, mainly 4X4 with a trac loc option and FE motors.The truck applications seem to have some better ratios than the passenger car applications.All the applications of the 9 3/8 I have seen have been 31 spline."

http://www.kevinstang.com/Ninecase.htm

[fordman]

i don't know about lockers or not but the 9 3/8 is made for fords it was in the differential identification pages.

[broke_okie]

I see they have been used in a lot of vehicles....i wonder if a detroit was ever made for this application? I was told the 9" drop out will fit into the 9 3/8 " housing with no probs or mods....is this true???

[390Nut]

Not sure about that. I've read before that you can use the 9 3/8's carrier in the 9 inch housing, but you have to clearance stuff to allow it to fit (why bother? )

[heep70]

Well, if you can squeeze the 9 1/2 into the 9 then I am sure the 9 will go into the 9 1/2.

Read that paragragh I posted.

[broke_okie]

yep read it ....good stuff.I do have that exact rear end that number listed is on the pinion bearing housing. I am just gonna try to find a 31 spline 9" and put the detroit in it and see if it goes in my housing. It might be difficult finding a 31 spline 9" with 3.50 gears but I might settle for any ratio as long as it is 31 spline and then buy the 4.56 gears I want .