Slant 6 timing chain lubrication?

I have never seen an aftermarket main bearing with the chamfer. I have only seen it on OEM bearing sets, and the factory service manual specifies this. I always do the chamfer
Don't forget to install the oil slinger on the crank. With the extra oil on the chain, you don't want to flood the front seal.
When did they start doing it? I just tore down a 66 225 today with original bearings and the front one was not chamfered. 66 date code bearings, too.