Ingredients
1 3/4  cups freshly squeezed lime juice, plus wedges for serving    
2 3/4  cups Don Julio Añejo tequila    
1 1/3  cups Grand Marnier    
2 3/4  cups guava puree 
Coarse salt, for rims

Directions 
1. Stir together lime juice, tequila, Grand Marnier, and guava purée in a large pitcher; stir to combine. Refrigerate until chilled. 

2. Just before serving, rub a cut lime around the rim of each glass. Fill a saucer with salt, and dip each glass, upside down, into the salt. Pour margaritas into glasses, garnish with lime wedges, and serve immediately.  Makes about 8 1/2 cups

Source:  www.marthastewart.com
Note: Recipe courtesy of Sue Torres