The forces on that BB are considerable , I tried fastening one with a pair of bolts @ 90' to each other [ M8 or M10 ] in steel and within 30km it was visibly moving when pedalled.
If using aluminum you can't use a rescued shell anyway.
things to take into account :-
BB axles are longer on one side than the other so the distance from the end of the BB axle to the centre of the BB is not half the BB shell width.
Chain sets have different off sets also IIRC 0mm / 3mm or 6mm
You may need a pedal on the other side that has a bend in it [ MTB ] rather than straight [ road bike ] for your ankle bone to clear the front frame.
Paul
If using aluminum you can't use a rescued shell anyway.
things to take into account :-
BB axles are longer on one side than the other so the distance from the end of the BB axle to the centre of the BB is not half the BB shell width.
Chain sets have different off sets also IIRC 0mm / 3mm or 6mm
You may need a pedal on the other side that has a bend in it [ MTB ] rather than straight [ road bike ] for your ankle bone to clear the front frame.
Paul