Here's the drawing that shows the distance from the back of frame to crossmember on my 71.
Yours may be different ... CHECK IT !
I must also mention that this modification was done using a PK OEM "Side cylinder" from a tractor earlier than 80. It has the slot machined into the chrome push rod & the Rockshaft Lever Bar fits in the rod slot. The "Back End" / "Dead End" of the cylinder has two ears welded on .. with thru holes for a pin. These ears are spaced to fit over 1" keystock for mounting..
I can only recommend these measurements when using THIS cylinder. Other cylinder lengths or mounting will likely require a different mounting measurement & style.
This drawing also shows a gusset that I welded in place when installing the mount. This gusset prevents any bending or twisting of the crossmember or the keystock mount. (Yes ... I abuse my tractor ! )
As for the plumbing ... as said earlier ... I used "Prince" Valves ... I don't remember what series they are or any part numbers. (maybe I can find some of my old paperwork if pressed.) I'm hoping that someone else can chime in here with spool valve part numbers or help.
I do know that these valves require that you buy a "Inlet Segment" ... then the actual "Valve/s" that you require ... then an "Outlet Segment".
The Valve Segment parts are all held together in a "Stack / Gang" by "Prince" supplied "All-Thread" & nuts .. of the correct length. The "Segments" have "O-Rings" between them for sealing to each other .... as the fluid/oil passes internally ... so eliminating a mass of hoses & fittings between separate valves.
I'll try to help by taking pictures or any way I can.