Okay, my research was a bit sloppy. Turns out there were Super Bowl preview issues for all but two of Super Bowls I-XV. For these 15, SI chose to feature one team over the other 13 times, picking the right team eight times. The first 15 "preview" covers are seen below. Worth mentioning is that in 1970, they featured the Vikings BEFORE they actually won the NFC title and then in 1972 did the same with Miami before they had won the AFC. Again, you can mouse-over the thumb to see how things turned out.