The clamp holding the exhaust housing could be placed wrong and holding the turbos up. The one holding the exhaust housing onto the center section can hit the I take manifold. I put a set of rebuilt turbos on and this same issue happened till I compared to the stock ones. It's just a vband clamp, loose it and turn it. Another option to try, happened with my max powers when I put them on my mock up engine. Hope this helps you out.