Differential Question pertaining to Resto...

[mcduck]

Have recently started the long process of restoring my '68 R/T.  I've decoded the car and it appears to mostly original... all the critical parts match (body, engine, trans, etc).

Only part in question is the differential.  My build sheet (which matches the car) says I should have a code 404/408 diff, which is a 3:23 Sure Grip.  As I understand it, this means it should be an 8 3/4s rear axle.  Though, clearly by looking at it, it is a Dana 60.

So, my questions are as follows...
1 - I want to restore to original, how hard is it to find a *correct* 8 3/4s rear end?
2 - How would I tell if a differential is coded correctly?  Is it stamped, have casting numbers, tagged???
3 - Would it hurt the value of the car much if I restored it with the Dana 60 under it and just found an 8 3/4 rear end that is correct which I could sell with the car later, if I decided to sell it?
4 - On the Dana 60, are there any stamps, casting #s, or tags I should look for to determine the gear ratio?  I assume it is a posi.  Just wondering if it is a 3:54 or something else.

Thanks in advance for the help.  I'm trying hard to keep this car as original as possible.  The rear end and maybe the exterior color are all I'm even considering not returning to original (ext/int is white w/red interior factory.  I'm considering going black w/red interior).

[41husk]

I your swapping your Dana for the 8 3/4, I doubt you will have any problem.  Make sure it's not a 9 1/4.  the sure grip rears are a little pricy but you should be able to find the correct diff for your car.

[gtx6970]

IMO
If your changing the color of the car, anything else you do or change is a mute point

[Chryco Psycho]

it should not be difficult to locate an 8 3/4
it should have a xxxx742 carrier
the car will be at least as valuable with a Dana diff
there could be a tag on the rear cover with the ratio & a second tag saying "use limited slip diff fluid " if it si a sure grip