if your tractor has the older 1 1/8" 6 spline pto.. get an ORC that is 1 1/8 female tot he standard 1 3/8 male for your mower.
grease and install.
make sure the telescoping pto shaft is not too long and bottoms out...
I like to run medium or light duty cutters on an 8n.. mostly due to weight.
howse 5' or KK 5' or kodiak 5' are fine.
if your hyds leak down ( fix them! ) or use depth limit chains that hook to a bracket that pins at the toplink and sets the max drop of the mower. I'd also reccomend a set of under axle swaw bars to keep the mower from swinging side to side on turns.
lil angle brackets mount under the axles using the fender bolts.. uses a piece of flat with holes in it to connect from a pin on the bracket and tot he implement pin.. etc. 1 is ok.. 2 is better..
if your tractor has the updatted 1 3/8" 6 spline pto.. get a standard ORC and use it.
note.. some quick connect orc's don't fit the N short 1 1/8 pto well due to housing size of the orc and interference at the pto bearing carrier where the oem pto cap screwed in.