tm9-801.com

http://theoldmotor.com/?p=48557

I'm amazed at how many people think that babbit is some sort of ancient alchemy or witchcraft. Most (nay, 99%) of the people don't know that even today, babbit is used in engines... but on easily replaceable 'shells' rather than having to be poured then machined.

Babbit main bearings can use shells (like the article) or be a little different there are no shells and you pour babbit directly into the block. You still have to provide oil holes and then line bore... but its really not rocket science.

http://www.nwo-modelt.org/blocks.html

Here is a model T block getting new babbit bearings. Note that the engine does not use shells, but must be poured onto the mains with the aid of a jig that gets you close. This article is missing a few steps... like shims, oil holes, final fitting. But this is all there is to it.