Full system weight for me on my gravel bike with 40mm tires is prob 10-15lbs less than you, I run 45-50psi on the road, and 30-40psi on gravel depending on conditions. That's tubeless tho, maybe lil extra pressure if you're running tubes. The goal is to find the right pressure for you that feels comfortable and stable, while not low enough to allow for pinch flats (if you're running tubes). Start at maybe 60psi and work your way down and find what works for you.