Happy to help..... perhaps instead you'd want to install one of the TI-based USB 3.0 cards that were originally created by HP to bring USB 3.0 to the Z400/Z600/Z800 and other fast workstations with a spare PCIe generation 2 slot to mount in. Those PCIe Gen2 slots can all let the card run at its full speed of 5 Gbps. That particular HP card includes a card "header" that allows bringing 2 of its 4 total USB 3.0 ports forward to the front of the workstation where I use an Akasa 3.5" form factor interface shown. This setup works great, and I have used it in the xw6600 and the Z400/Z600/Z800 workstations.
At the bottom of the post HERE I have a post that links to 3 others on that process and includes part numbers and pictures: