Ivan, as near as I can tell with a tape measure, the left crankcase is 3 inches or maybe just a hair under.
I don't have a cover off at the moment to measure the other dimension for you. Hopefully someone else can.
2014.5 Kawasaki KLR650 NE-2008 Yamaha TTR110-2006 Buell XB12SS-1993 Kawasaki KX500-1984 Honda XL600R/XR650L Hybrid-1984 Yamaha TT600L-1980 Honda CB750F-1977 Yamaha TT500
For sale--1996 Honda XR600R--