Well, it depends on the Saleen set up---as my experience has only been with the whipple. Not sure of the limitations of the Saleen s/c. But I did pick up +23rwhp when I switched from the stock TB to the BBK throttle body. And--how does the BBK TB compare to the GT500 TB?
I guess if you decide to keep the Saleen s/c, you might as well wait for the mono blade set up and do it only once. But when I went to the mono blade (black diamond 1600cfm), I changed the CAI and the manifold to the back of the blower---as the setup will only flow as much as the weakest link.