You are looking at the wrong thing. You need to look at piston compression height and it is the same.. I used to work for Dana at the tech center when they had both there brand (Perfect Circle) of after market parts as well as supplying the same parts to NAPA, I am going to help my son this weekend  and do a little carpenter work. Send me a regular  e-mail  address and a phone number  and Iwill get back with you next week. Tell me a good time to call. On Tuesday evenings I teach an adult hydraulic lclas sfor the local JVS, Where are you located? John