[sparkycuda]

Thanks for all the responses. I worked on/taught 1:1 heavy equipment, but don't have experience with how the RC world is different for fit and finish of hydraulic pieces.

My Payhauler requires four stages to get retracted pin-to-pin centers at 3.9" and extended at 9", like the real one. Did learn about the differences between SAE hyd numbered o-rings and plumbing numbered o-rings: there are not the same dimensions. Plumbing #008 are 3/32" CS while hyd #008 are .070" CS. Makes a huge difference for groove and barrel fit.
Aw, the things you pick up while building stuff!

Ken