Hey, thanks for the replies, sorry for late reply here. Newbs here have very limited posts initially and I got locked out.
Yes, I have threaded english standard. I think I'm getting the picture of these things now. Thanks for the info and links.
I see I was reading about pressed bearings in two regards: pressed into the frame and pressed into some sort of screw-in holder. Confused me a bit.
have been totally out of the loop regarding BB developments for quite a few years. It's the thing I touch least often on a bike. I have been lucky with BBs; they seem to last me 5 to 10 years even with huge mileage.
I found a good deal on a shimano xt m-770, lightly used, so grabbed that last night. New bearings are very cheap. I hope it goes well. Looking forward to what looks like easy bearing swaps in the future. Hope they don't creak and do hold up well!