L295DT Model 1200 hydraulics

I've got a L295DT with model 1200 loader. The hydraulic lines to the loader valve are connected to an aluminum block on top of the tractor's pressure relief valve (under the left side of the tractor's seat). I'd like to operate a 3PT tree spade on the tractor that has an open center valve. My question is - can I merely attach the tree spade valve in series with the supply line going to the loader valve, and any particular style of quick connects I should use?

Thanks!