New old stock number four main bearing for 356 / 912 pushrod engine with three piece case.  Standard crank, first oversize line bore on the case.

This is an unusual bearing and not currently offered by Porsche.  All alloy, not steel backed.  If your third piece bore is a little oversize and needs a line bore, you will need this bearing.

There is a small amount of scale from age on the inside bore which will need some hand work before using.