I don't think the gain is worth the extra $$$ of the swap IMO. But if I was gonna do a swap like that I would be buying ceramic coated headers and them alone will cost around $400 not to mention a H/X pipe. So you talking in the $$450-$600 range to make the swap for about 5-10HP maybe 15
and probably about the same torque. Not only that, you may have to unbolt the headers or atleast one when you if need to pull the trans. I know we had to on a friends car with a T-5 and BBK long tubes. Now I could see if you were an all out drag racer and needed every bit of power and torque, then it might be worth the extra to be competetive. But this is might $.02 on the subject.