Likely going to get conservative info regarding bearings from a parts vendor. NASCAR open Cup and NHRA Pro Stock both use 1.850" dia. x .650" wide rod bearings in the real world. I'd be more concerned with crankshaft integrity due to the decreased overlap, I have a 2.500" main 4.000" stroke 1.888" rod journal 8800 rpm drag race deal I work on, that I'd go back to a larger rod journal if I could. Even though it's an 8 counterweight crankshaft, #2,#3,and #4 main bearing wear patterns tell me the crankshaft just doesn't have enough overlap for the application, and is hurting performance on the track.