When it comes to the line pressure on a 68RFE, there is no one-size-fits all answer. The correct line pressure for your specific application will depend on several factors such as engine components and any modifications you may have made. Generally speaking, the ideal line pressure for a stock 68RFE transmission should be around 150 psi during light throttle applications, and up to 175 psi under heavy load conditions. However, if you’ve made any changes or additions that could affect how much power your engine produces—such as installing an upgraded turbocharger or tuning software—you should aim for higher pressures. Keep in mind that running too low of line pressure can lead to premature wear in the clutch packs, while running too high can cause excessive heat build-up within the transmission system which can further damage internal parts over time. It's always best practice to consult with a professional before making any adjustments to ensure your setup is optimized properly.