The 262, 266 268 and 272 I believe all share the same crankcase. Part # for the models made from 1993 on for the 266 crankcase are 501 68 52-63. thats the complete case, right and left halves, sorry, I cant find numbers for each individual half.
I've got a running Jonsered 670, generally a husky 266 with a different carb on it. if you want it Pm me.