Ummmm... YES they are...
CR250 1997-01 66.4 66.40 PK1168 $202.76 702M06640 $155.34 2614CD S508 W5319 B1003
Pro-Lite x 67.00 PK1169 702M06700 2638CD $38.00 $15.70
Nikasil Bore 72 67.50 PK1170 702M06750 2658CD CW18
68.00 PK1171 $217.84 702M06800 $170.88 2677CD
68.50 PK1172 702M06850 2697CD
Racer's Choice
Sorry, poor copy / paste, but it's from the wiseco website.
http://www.wiseco.com/Catalogs/Powersports...daCycleDirt.pdf