hi
Ryco have recently modified there c/cans
Old Rcc 350
New Rcc351

1st mod
****filter has one end [bottom ] 90 % enclosed
Why I suspect to restrict oil slosh from being sucked into outlet which is at the other /top end of filter

2nd mod
Outlet located at top of filter has alot larger baffle
WHY,, To prevent excessive oil from being sucked thru c/can ie slow the air so it can return more oil to storage area

3rd mod
pressure regulating valve located on the top out let
Function ,, to protect filter media against un needed pressure waves
problem ,, this restricts flow
solution ,, the later Rcc has this removed