NASCAR engines run rod bearings in the 1 7/8" diameter range at 9K+ RPM and over 600 HP. The size of a bearing journal is pretty much immaterial, as long as the oil clearance is right and the oil pump can supply enough lube to keep the metal parts suspended on a film of oil. If anything, smaller diameters of bearing journals are better, because the slip speed of the surface of the bearing is lower, making the job the lubricant has to do less stressful.

It's possible to bore the big ends of Babbit lined rods for an insert bearing. Instead of using the scarce and incredibly expensive dedicated bearings that have been available for decades, I've found that a rod bearing for a Perkins 3 cylinder Diesel has the right outside diameter, but the crankshaft journal needs to be ground .060" undersize to fit the bearing. The upside is that the bearings cost about $5.00 each, and several undersizes are available that would allow further regrinding of a shaft that would need to be scrapped otherwise. The stroker crankshafts I'm working on to dramatically increase the displacement of stovebolt engines are also using sub-2" rod bearings.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
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