Very good if built right is what I will say johnny same as Phil and a few others in the know, like any thing they will fail from abuse and not changing the oil in them as the gears run on needle roller bearings in them, ppg had an issue with sleeves slipping inside the gears on there older gearset sand they have now redesigned them to the same as par. The weakness left is not changing the final drive the standard nissan shaft is worn on a lot of gearboxes and there are starting to fail now...I personally am not building them anymore due to the slagging I have had with no proof.