Can a man who is of Ashkenazic ancestry and has worn an Ashkenaz-type tallis since getting married allowed to wear (and make a brocha on) a talis that has Safardi-type tzitzis? He does have other Ashkenaz-type talisim but he received the Safardai-type as a gift (non-returnable) and would like to use it. Thank you for your kind attention to this matter.
Answer:
The question of how to tie the tzitzis strings is a matter of custom, and there is no doubt that the Sefardi-style strings are also valid for Ashkenazim. Therefore, you can wear the tallis and make a berachah on it, without concern.
However, because your custom is to wear Ashkenazi tzitzis (and you are of Ashkenazi origin), it is preferable to change the strings to the Ashkenazi method of tying them. You can keep the actual tallis, and only change the strings. This is not a matter of urgency, but it remains preferable to change back to the Ashkenazi method.