Not a clue why they list different sizes for different trim levels. From a fitment standpoint, a 225-75 will certainly fit, with no problems. I'm currently running 225-75's on my '94 sport, and ran the same size on the '87 Pioneer I used to have, and have never had a problem with either. One thing to keep in mind is that changing tire size will affect your speedometer accuracy. My '94 Sport had 205-75's on it, IIRC, when I got it, and the speedo was off. Changing to 225-75's put it dead-on accurate. A 215-75 is 27.7 inches in diameter, while a 225-75 is 28.3 inches in diameter, a difference of only 0.6 inches.
4-wheeling: because football, basketball, baseball, and golf only require one ball!
Confidence: The feeling you get just before you fully understand the situation!