BB Confusion!
 

so i just picked up a 70's peugeot frame for $20, and i'm really confused about replacing the bottom bracket. should it be french threaded? and are these apparently hard to come by now? any help would be great. thanks.

Hello,

It depends on the model/year of your bike. If you could post pictures of the bike and/or any serial numbers you might find on the frame or parts, we'd be able to help you better.

Richard

Been there ... done that.

An early-to-mid 1970s Peugeot will definitely have a French-theaded bottom bracket.
An early 1980s Peugeot will definitely have a Swiss-threaded bottom bracket, usually denoted by a gold anodized fixed cup.
If you have a late 1970s Peugeot, please let me know what you discover, because you are outside my experience and expertise.