That seems the most logical. However, when the original combiner valve is installed, the 3pt works perfectly and the only two holes plumbed and active from the tractor are the ones labeled 1 and 2 on the pic above. The center pipe port 1 of course being the pump feed and the port 2 being the return to the 3pt cylinder. But, when I installed the new Cross valve, the port 2 from the tractor doesn't join any opening on the Cross valve, so it's sealed. But, I'm still able to raise and lower the 3pt using the Cross valve, so somehow, oil is getting to the 3pt cylinder, and the ONLY possibility left is the port 3 as shown on the pic above. Leading me back to what exactly is this port? I do have a multipower transmission so could this other port 3 be something related to that?