BOSTON ( TheStreet) -- International revenue growth for big U.S. companies such as Johnson & Johnson ( JNJ) and PepsiCo ( PEP) is the one saving grace as the domestic economy grinds to a halt. Too bad the benefit of currency swings masks the real story.U.S. large-cap companies are finding more opportunities in emerging markets. In previous quarters, the weakness in the dollar has made it cheaper for foreign countries to buy consumers goods from U.S. corporations. That resulted in American companies producing faster sales growth overseas.