I picked up my case and crank from the machine shop and am trying to determine which bearings to purchase. Starting with the case and crank:

Measurements from the machine shop are:
crankshaft housing bore sizes:
#1 2.757"
#2 2.757"
#3 2.757"
#4 1.970"

according to the workshop manual section 0.2-2.2 tolerances and wear limits:
bore for crankshaft bearings
#1-3 2.7559-2.7567"
#4 1.9685-1.9701"

Measurements from the machine shop are:
crankshaft main journal sizes:
#1 2.3612"
#2 2.3613"
#3 2.3614"
#4 1.5740"

according to the workshop manual section 0.2-2.2 tolerances and wear limits:
#1-3 2.3610-2.3618"
#4 1.5740-1.5748"

All this looks to me to be standard size bearings but I am asking for comments and observations etc, TIA.

Does that make the 1,2,3 bores 33 ten thousanths over the high side?

hmmm, I don't know. It looked to me to that the measurements matched to factory measurements. 'Splain your observation to me, I would have said 11 ten thousandths at worst and 3 ten thousandths at best.

First Jim, let me explain that sometimes my dyslexia takes over when dealing with that many decimal points and i get confused.
That said, 757 thousandths =7570 ten thousandths. Correct? That would be 3 ten thousandths difference, not 33. I'm no machinist, so I'm looking for the right answer too I guess.

Part of my inquiry and posting of this thread is to see if someone will explain what these numbers mean to a novice like me(/us). For an air cooled engine, do you get concerned about numbers in the ten thousandths range? All will boil down to "what bearings do I need to buy?"

Ok, so most of the measurements are in the midrange of fittment and look to be standard.

What you really want to know is:

1.) Measure the ID of the bearing installed in the case or rod and torqued to specification.

2.) Measure the OD of the main journals and crankpins.

3.) Subtract the OD from the ID to give you the running radial clearance of the bearings.

A bore mike is especially useful for this.

If they haven't been machined down (the case bores and the crank throws) they will be even mm sizes or very close to it. For instance, 44.97mm (45mm) or 120.01mm (120mm) rather than milled to .25mm increments. 1/4mm is very close to .040", the standard machining step.
So, if the parts measure very close to even millimeters and they are within the wear specs you can order standard bearings. If they're .25mm smaller or bigger, that's 1 step, .5mm, that's 2 steps, etc. If they're out of spec you need to machine them and order thicker bearings.
The 45mm and the 120mm numbers I posted are arbitrary numbers, nothing to call the machinist about.

Those look like Std bearings. You're lucky. I had my case align bored and now am having a hard time locating main bearings for an oversize case. I am actually using some new bearings with a used thrust bearing.

Be very careful. Main bearings are NOT available for oversize case bores!