Pls note this is Chap Saw. I'm not responsible if your dimensions turn out to be not true though I'm 99.9999% sure they are as these were taken of the service manual and assuming your engine is a Nissan QG18DE. Pls have your engine builder to properly measure your rods to be 100% sure.
Centre Distance (conrod length) mm(in): 140.45 - 140.55 (5.5295 - 5.5335)
Rod Stroke Ratio: 1.597 (88mm stroke)
Bushing Inner Diameter (small end) mm(in): 19.000 - 19.012 (0.7480 - 0.7485)
Big End Inner Diameter mm(in): 43.000 - 43.013 (1.6929 - 1.6934)
Side Clearance Standard mm(in): 0.200 - 0.470 (0.0079 - 0.0185)
Side Clearance Limit mm(in): 0.52 (0.0205)
QG16 and QG18 runs the same conrod. QG13 to QG15 too if the service manual is to be believed. The difference is in the cylinder bore/piston diameter. It also shares the same conrod dimensions as the previous gen GA16DE engine. The stock conrod is a forged steel item and relatively strong for the engine's stock power output. Piston dimensions to follow.
Have a Great Chinese New Year Everyone!!!