Thank you for your response. In the interim, however, I found my grandfather's naturalization papers, which indicate that he did not come in to the US through Castle Garden, but through the Port of Boston in September 1890. I assume the same advice applies, but so far I have been unable to find my grandfather's name on a ship manifest arriving at Boston by using Ancestry.com. As you suggest, I have used many combinations and spellings of his name. His name on the 1892 birth certificate of his eldest son is listed as father: Ike Yurovsky. He later lived in Passaic, NJ and did business as John Yurow and was buried in the Lodi, NJ cemetery as Isaac Yurow. Still no luck, however, in finding a "Yitzhak Yurovsky" (or any variants such as Jurovsky, Yurowsky, Yurovski, etc.)
Any ideas will certainly be appreciated. Again, thank you for your help.