rear end?

I was told you have to buy a new rear end when you buy gears for your car. I think this is complete BS becasue the guy who told me was a transmission guy wanting to make some extra $. He also told me when i buy gears, i would have to get a new differamtial cover. Your thoughts???

i dunno how it is fer the new cars.. if its even that differnt but for gears on my 76 i just need a new carrier if i got over 3.08's... well im just goin by what it says on the auburn gear website

He is BS'ing you.

While the rear end diff cover isn't a bad idea...it isn't needed.
The entire rear does NOT need replaced to swap gears.

Only certain cars with certain rear ends would that be sort of true. On the third gen bird I have I have the Aussie rear end that only came with 2 gear ratios from the factory and the carriers dont support aftermarket gears. And Im not sure Im 100% believeing that...like someone said earlier you may have to get another carrier but that should be it.

wat are gears?

The rear end has gears in them.

I don't explain it well, so....
http://science.howstuffworks.com/gear-ratio.htm

That might help.

oh the ause 9 bolt rear end they can not rebild or put gears in, i don't know why but it is weird.