For that combo, imo, if you're only turning it 6300, you're not revving it high enough for the 2" to be of any real benefit.

The 1 7/8" Hooker fenderwells make big tq numbers, in part because they're so long........so you def would have taken a little step backwards in the lower part of the power curve by using 2" TTi's instead.
May not matter with 5000 stall though.

If you're primarily running 1/8 mile, then it would be even harder to exploit and possible gains from the 2" headers.

Not what you asked...... But...... The cr seems a bit low for a 270@.050 cam.
Not sure it would be worthwhile to swap it, just saying it wouldn't have been my first choice, especially for the modest rpm you're turning.

What are the performance numbers out if the car?