1968 Cadillac Posi Rear

[Mechanicville]

Hey guys,

I'm looking to buy a posi center section for my 68 coupe deville pro touring project... I think your commercial hearses and ambulances have a taller gear option then the optional traction control 3:31 from the passenger cars.... Anyone know what I'm talking about ...

[60Crown]

How about adding your location so one of us can relay if a parts coach is sitting nearby?

[Mechanicville]

Of course... Thank you.. I'm in Maryland

[60Crown]

NHAA member Shawn of the MPCC near Reading, PA may know a rear end closer than the NC units I have in mind.

[Mechanicville]

Does anyone know what ratios were available on the commercial vehicles of 1968? Also... I'm not so sure what other years could work for me in my 68... Any info would be very much appreciated...

[60Crown]

Have access to and already plan on checking a '71 master catalog in next couple days for those specific answers.

[Mechanicville]

That's great!!!!! Thank you very much

[Psychoholic]

I'm still interested if there is a different center section that we could swap in and have some axles done (some nice Mosers or something).

Maybe after I grenade the one in Morticia (after I get her back eventually), I'll take the parts to Auburn and see what they can do for me.

[Mechanicville]

I'm not so sure what your talking about psycholic... I'm just looking for a few car parts...

[60Crown]

Glad that you posed this question as I enjoy learning something new that hadn't been covered before. Here's the commercial chassis breakdown, sans parts numbers. Repetitive gear ratios listed different years means different parts numbers.

'56 3.77 ('57 not listed, assumed same part as '56)
'58-'65 3.77
--->'62-'65 control differential option, different part number
'66 3.36
'67 3.36
'68-'69 3.21

[Mechanicville]

Thanks Atti... 3.77 would be a good ratio for my project. I wonder how the 58-65 rear differs from my 68 rear.. I think I'm almost done considering this path.. I was hoping it could be an easy solution.. I think a ford 9" or a 12 bolt may be the way to go.. My stock rear is approx 59" long from flange to flange. Its not very hard to find a ford rear close in length and weld on the appropriate tabs..