i have a 91 bird with a non posi diff i found a posi carrier from a 95 bird with 3.73's can i bolt that carrier into my rear? are their any adapters or spacers that are needed?

 

Yes you can bolt the carrier in.

Whether or not it will work, depends on what series of carrier it actually is, and what gears you actually have.

If it's REALLY a 3 series carrier, and not a 2 series carrier that had either the "special" thick adapter gears or a spacer, and you have a 3 series gear in your car (3.23 or higher), then it will work. If on the other hand you have 2 series gears (3.08 or lower), then it will ABSOLUTELY NOT work, and there is no possible way to make it work with those gears. Unless of course you know where to buy a spacer that takes space out, instead of putting space in. I did used to know of an Internet site that had those; they were on the same page with the drill bits that drill square holes, and bolts with a 5/8" offset in them for putting late-model starters onto early model blocks; but I lost the link.

If it's REALLY a 2 series carrier, and the PO did have either the special gears or a spacer to put the 3 series ratio on it, then it WILL work; provided that if you have 3 series gears (3.23 or higher), you use a spacer.

 

sorry forgot to mention the carrier comes with a set of 3.73 gears so its a compleet unit i just want to know if i had say a 2 series can it be replaced by a 3 series with the 3 series gears

 

The housings are all the same, as far as gear series. So yeah, as long as your carrier and gears match, they'll go in.