I recently purchased some hitachi su's for my old mans ute (720 with a l18) i think i now were everything connects to except for two things , are the two nipples on top of the floats just vacum or are they something else ?

Cheers Alfie

The nipples are for the fuel supply to each float bowl.

yea i have got them hooked up theres another nippile on the front top of the float

overflow just let it piss out onto the ground

You will need to fit a hose to the overflow[s] and route it well below the exhaust to prevent a fire.
Usually, the o/flows are attached to a bracket off the sump flange.

or could i just run it throught to the emissions pot which in turn will run back to the fuel tank if thats correct

kool always wanted flames coming out of the exhaust good tip haha

If you mean the carbon canister, no.
That is only designed to handle fuel VAPOR from the expansion of the fuel in the tank, not raw fuel.
The o/flows are there in the unlikely event that the float valves get stuck or the float chamber overflows.
If they are in good condition, it may never happen.

ohh ok thanks for your help greemes50