33x12.50R20 is 0.22" taller than 295/55R20, a +0.68% change in diameter, inside the 3% range most shops treat as a safe swap.
Ground clearance changes by 0.11" (half the diameter change), and the tire needs 0.11" more room above it.
33x12.50R20 is 0.89" wider. On the same wheel offset about half of that, 0.44", moves toward the suspension and half toward the fender.
Both fit a 20" wheel; the sidewall is 0.11" taller on 33x12.50R20.
Details: 295/55R20 in inches · 33x12.50R20 in inches · change sizes in the calculator