4500 stall is too much for a turbo, they like to PUSH on something! I would try the stocker first. I would even go lower on the rear gear but your deep into it now, make it work! :-)
its 4200 on the brake. He told me it would be closer to a 3500 when foot braking it. I did not pick it. I gave dynamic all my info and they told me what I needed. I have no idea how to size converters and left it to the pros. I hope it works well! it was an expensive piece. I do plan on taking the RPM to 9500 or more with this small block.