How does one choose rod bearings for aftermarket rods?
 

It's easy with Honda oem rods. Match the crank casting with the number casting on the rod and choose the correct color bearing for each rod.

Although I have never actually purchased aftermarket forged rods (or aftermarket rods in general) I suspect that it's not as easy as just looking at some castings, unless of course the piston manufacturer decided to be super helpful and mimic Honda's technique.

So, without this quick easy color code technique, how exactly do you do it?

My only guess would be to use a very accurate micrometer to measure the rod journals and a bore gauge to measure the bore of the rods large hole. Calculate the exact difference between the two, look up the oil clearance specs for the engine, and find a bearing who's specs will put your oil clearance in acceptable range. I suppose this would work, but I'm wondering if there's another technique?

I would think the rod seller should be able to give you the spec's of the rod....I'd almost bet they would even be able to help you with which bearings to use.

If the crank has not been turned then use the factory spec's - get a set of bearing and then use plastigauge to verify the clearance and taper.