In Reply to: Re: 9N main bearing studs posted by JimN on September 30, 2020 at 09:29:09:
Personally I think a good machinist owns a bore gage and knows how to use it to accurately measure bearing clearance. Plastigage is for ill equipped amateurs.
An engine builder can easily get within the .0025 clearance on a line bore. That would be the outer limit of what I was happy with.
If I understand your concern it is cap registration on reassembly after machining the caps.The L-head design does not have a cap registration recess in the block like a modern engine. Which begs the issue of what the engineers felt was needed.
I see no need for sourcing beat to death OEM studs to achieve that end. Any engine builder worth his salt should be able to make after market studs act as a register. If you believe it is important knurl the shoulder to get an interference fit on the caps. I think that is as good as it gets given the design.