This has been mentioned before, but evidently it's not quite the same thing. The main bearing inserts are old stuff - they used to just use 2 sets of bearings nested.
Inserting the donor bearing (the one that fits the replacement Buick, Dodge etc. rod) around the actual bearing hasn't been tried that I know of.
Shouldn't been too tough to pin the donor bearing to its rod and cap, assemble and hone the ID to the finished size of a bare 292 or GMC rod big end. This means that the donor bearing ID must be smaller than the 292 etc. rod big end.
Now insert the 292 bearings, and pin them to the donor bearings.
The oil reaches the 292 bearing normally, the only rotating contact is between the journal and the 292 bearing - the right one. Downside: extra weight, larger big end OD for cam clearance.
Now... who's going to be first to try it?
