Is bigger better ?

I am building a mild 450 horse 440 I a 69 a body with a nice sounding cam, 10.1 compression, nice intake,, standard 906 heads with ports matched… question is :are 1 7/8 headers big enough or do I have to go 2 inch,, I want a 3 to maybe 6 k power band.. thanks in advance
Yes, 1 7/8 are big enough for more power too.
Tti headers I'm guessing?