Maybe it's just me,but I don't think you will see much of a gain until you put the bigger camshaft in it.
On the header subject,1 3/4" headers seem to be the ticket with mine. I ran 1 7/8" before thinking they were necessary. My dyno testing lately shows a hole in the torque curve that just does not get made up for up top with the bigger headers.
In anything that launches at or below about 4500 rpm anyway,I am learning to like 1 3/4" headers more and more.
Keith