If U Upgrade Exhaust Must U Upgrade Intake

[scruffboy]

I posted this as part of another thread, but maybe nobody's reading it. I could really use some help on this. Here's what I posted:

I bought the Magnaflow with the 2 1/2 inch dia. pipes because this summer I would like to install header with 2 1/2 inch cat back exhaust. If I do this, do I have to make corresponding changes to the intake system? The guy at the shop showed me this shiny "open air" intake, but if I hook it up to the same throttle body, what good does it do? Also, what about the computer, which I know nothing about. The last car I worked on for speed was a 69 Camaro, and I just threw on a Holly highrise manifold, 4 barrel carb, and a set of black jack headers. Man, that small block 350 chevy roared. But hey, those were the good ol' days, right! Maybe I should just stay stock, I don't know, but I would like to have a project for the summer.

Sincerely and with lots of gratitude to all,

James in NJ