Shimano integer replacement BB?
 

i got an old schwinn with the integer cranks and bottom bracket. someone stripped out the cranks, so i was thinking i would just replace the whole bottom bracket and crank set up. the only problem is that the bottom bracket has pressed cups, and there for no threads in the bottom bracket shell.

so is there any way to replace the bottom bracket? i was thinking that the YST no thread BB might work.

if that wont work, where can i find some replace ment parts for this thing?

thanks