Hyd Roller vs Hyd Flat tappet on SM heads

I was over looking at the SM heads and noticed they have the fully assembled heads advertised for hyd roller, and hyd flat setups.

My understanding was that rollers needed heavier spring pressure due to weight, but these two pages show what appears to be the opposite.

Mopar Chrysler SB 318 360 170cc 65cc Hydraulic Roller Assembled Cylinder Heads
Max Lift: .600
Coil Bind: .1.150
Intake Install: 135lbs @ 1.8
Exhaust Install: 135lbs @ 1.8
Closed Sear Pressure: 135lbs
Open Seat Pressure: 325lbs


Mopar Chrysler SB 318 360 170cc 65cc Hydraulic Flat Assembled Cylinder Heads
Max Lift: .600
Coil Bind: .1.060
Intake Install: 145lbs @ 1.9
Exhaust Install: 145lbs @ 1.9
Closed Sear Pressure: 145lbs
Open Seat Pressure: 360lbs

These seem to contradict what I've read. Is it just a mistake or is there something I am missing?