Topic: 1968 GT 390 Drive Train Advice Verification

[J_Speegle]

Thanks Jeff do you need to see any other photos to help ID this diff

I've seen enough to believe its not the original. Now for identification purposes for resale or finding it a new home compare it to Bob's pictures

[bullitt68]

Which type do you have the "N" case or the single vertical rib?

Hi Bob I will have to confirm which case I have next time I get to the shop to have a look, but I don't recall seeing a N on the case. It read that the C5AW-4668-C is an early Ford design, but the case seems to be a 1970 case, so perhaps the carrier and case are from different cars. I will try to get some better photos next time which will hopefully shed more light on what I have.

[bullitt68]

Which type do you have the "N" case or the single vertical rib?

Hi Bob Looks like my diff has an "N" on it

[J_Speegle]

Hi Bob Looks like my diff has an "N" on it

Thought that might be the "case" LOL when I saw and mentioned the "extra" rib earlier

You'll be able to find a new home for that also

[bullitt68]

Thought that might be the "case" LOL when I saw and mentioned the "extra" rib earlier

You'll be able to find a new home for that also

I guess I just need to confirm if it is a 31 spine and what ratio it is. Would I be correct in assuming that this would be a SCJ application

[J_Speegle]

I guess I just need to confirm if it is a 31 spine and what ratio it is. Would I be correct in assuming that this would be a SCJ application

You'll want to figure or number of  spline and gear ratio. So far we've focused on the case/third member so it was originally used in a 1971 (given the casting date) CJ, SCJ or Boss 351. Not sure if any other engine combination that year also used it but that is the big three

[bullitt68]

You'll want to figure or number of  spline and gear ratio. So far we've focused on the case/third member so it was originally used in a 1971 (given the casting date) CJ, SCJ or Boss 351. Not sure if any other engine combination that year also used it but that is the big three

Yes and also will need to determine the value as well. I will have a list of parts I should post to see if anyone wants them and then a list of what I am looking for. Obviously some of the parts might not be worth listing and perhaps a few could be of interest to someone