8 3/4 center section interchange?

[GoodysGotaCuda]

It's been awhile since I've played with an 8 3/4, so I'm rechecking. I currently have my original 1972 8 3/4 differential, with a 489 case 391 setup in it. If I were to find another 3rd member from the junkyard, it should drop right in, regardless of it being another 489, 741, etc, correct? Is a gasket usually used on these, or just rtv? Just planning on swapping to maybe a junkyard 323 or so if I can find it, since we may do some distance car shows in Laughlin or something. 391 is definitely not likin the highway cruise!

Thanks

[ntstlgl1970]

They all interchange, things to look out for are the pinion yoke size, so if you have the small ujoint, you would need the conversion ujoint for your driveshaft. Any good parts guy should be able to get one for you. On the gasket, can go either way. Some guys don't run one. I don't think it is an issue. If possible try and get a 742 case sine it doesn't use a crush sleeve so the odds are better that the pinion bearings are ok IMO assuming you would just swap it in.

[Chryco Psycho]

FelPro makes a gasket for the swap

[GoodysGotaCuda]

Thanks guys, I believe I have the coversion joint as of now. If i remember right the diff has a larger yoke and my car came with the smaller (open 2.76).

Thanks-

[dodj]

I just bought the gasket from Mancini's for a bit over 5 bucks. I was wondering if I should be using RTV with it as well. 

[Chryco Psycho]

I do

[dodj]

Then I will.