we usually call wall lake,ia.it is an independant salvage yard. also try worthington,mn. they are connected to quite a few other salvage yards. should be a lot of late 1400 series showing in their yards.
The later 1600 series didn't have 2 relief valves(primary and secondary)in the valve. Back by the pump was a cartridge relief like used in the 06 thru 86 series tractors.This was the primary relief. They were nonadjustable.You would just have to add this same relief block to your system.The secondary relief is in the valve as it has always been. I want $500 dollars for this header lift valve.