Depends on the bike. If it's an older Peugeot then it'll have a different thread to normal so you can't change it. Pretty much everything else you can fit a modern sealed BB in its place. Measure the width of the axle and buy the same width sealed BB and it should be a direct swap.
The Tange ones with metal cups both sides are good quality and a sensible price. Should be about £15.
Cheers, its going on a colnago super, from the early 80's, with full super record parts. Wanted to use super record bb but as no one sees it, ill use something modern and maybe more reliable
Tommasini tecno extra, De rosa slx,
Masi Prestige SLX, Colnago master pui, Pinarello concept genius c record, Ernie Clements 531,