VICKERS RV3-10V-C-0-3/

This Vickers valve is rated to handle pressure up to 350 bar, which is about 5000 psi, so it's built for some pretty tough hydraulic jobs.

Harvesters are actually one of the listed applications for this valve, so you're in the right ballpark. It's rated up to 350 bar (5000 psi) and handles flow up to 300 L/min (80 USgpm), which gives it plenty of headroom for most harvester hydraulic circuits. The poppet-style construction is part of why it holds up well in those situations, poppet valves tend to stay tighter over time with less internal leakage than spool-style designs, which helps keep pressure regulation consistent even when demand fluctuates. The rated flow for this specific configuration is 76 litres per minute, so just make sure that lines up with what your system is actually pushing through that circuit.