Eddie B., thank you for clarifying whether this information applies to earlier models than what your scans specifically call out. You posted this info a few weeks back and I wasn't sure whether it could be applied to the D4600. I'll definitely need to have shims made, but won't know what thickness to go with until the counter bores are cleaned up.

Now I'm worried about the new liners I have and I'm kicking myself for saving $60 a sleeve +/-. Cat still had them in stock at the time. Buy once cry once?

Thank you Eddie, OM, and Rome for your help.

a poor mans indcator can be made using a piece of soapstone(engineers chalk) in the tool rest of the lathe turn the liner slowly by hand after making sure its mounted true in the chuck advnce the saddle close to the liner where chalk rubs on the liner it is out of round if a nice even mark all round then its not out or out by very little a scribe and bearing blue can also be used.
note this only give you a idea of if its out it still needs to be properly checked with a dial indicator.

My block is at the engine shop in Fresno. The machinist recommends decking the after truing up the counter bores to get the right liner protrusion, rather than make custom shims. He then would shave the top of the piston to prevent it from protruding too far at tdc.

I know this is done with modern engines, but I'm a little nervous proceeding like this. It appears Cat's preferred method of adjusting liner protrusion was by using shims. On the other hand, maybe that was for convenience and field repair.

Any advice on how to proceed? The shop is very reputable and does work for Quinn Caterpillar. They just don't deal a lot with engines built in the 1940s.

I would only deck the block as little as possible to make sure it is flat. If you have too much taken of the deck, there will be nothing left for the next time the block my need repair. Follow the procedure for measuring protrusion and shim liners as needed.

I'm not a fan of unnecessary block or piston material removal. Top ring land needs all the thickness it has. Acquiring the necessary shims may be a hassle but it's the old tried and true method used on these engines.

Thank you OM and Tractor Dan. I will proceed on that basis.

you only want to machine a block or head by the absolute minimum as this changes the compression ratio. increased ratio means bigger bang which means more force(that's the idea of forced induction by increasing the pressure and mixture density higher output is obtained) which may unduly stress something. best to do the bare minimum and follow the factory procedure for max reliability.