It all has to do with the offset on the rim you're using. A good tire/wheel shop can help you out there. You might find one that has a setup rig that bolts to your rim & shows the fit at different offsets and tire sizes, but thats a bit rare unless they do alot of custom work.

You'll always be able to fit more under the rear than the front as you have to look at what sort of clearance you need as full turn for the frame and fender. One reason why you'll see some rigs with smaller front tires.

1956 GMC 370 dump " 'Tater "
1970 VW Volksrod "the Black Bomber"
2007 Chevy Avalanche
2020 Jeep Cherokee Trailhawk,
2005 Harley Davidson FLHTCUI

I dig all cars, old and new, whether they were hammered out of American iron, German steel, or Japanese tin cans. Being unable to appreciate them all is missing out on a world of great things.
But thats just MY opinion! :P