All of them that I have came with the washer. If you all need a pic of the difference I can post them. But they are different. I believe Cudas all came with stabilizers. Could be a performance application. I never had a cuda without a 340 or 383. Or for that matter any cars besides 340 or big block with a stabilizer. The K's may be reinforced for the heavier T bars which usually came with stabilizer option standard.