The front bumpstops are merely pimples compared to the rears. The rear stops are about 5.5" long and (on my 4x,xxx mile example) only 1.25" off of the axle when at rest. By chopping them down (can be done on the vehicle, but easier and neater to unbolt them), I gained an extra 2" of axle travel before banging into the bumpstop.

I also run my Ranchos at 4 front and 6 rear (on the street).
I have a seriously bad back from a (few) parachuting incidents and these settings work well for me -they should be fine for an old man like yourself