[West Coast GTO]

I am in the process of changing out the Hooker headers on my 71 GTO to RARE exhausts( oversized and 2 1/4"). I am surprised to see the relatively small exhaust port on the Edelbrock heads. I know I am losing some flow from the Hookers larger tubes but, since the E heads have such a small port area, it doesn't appear to make much difference.
Heads are out-of-the-box and don't look like any flow work has been done on them.
Would there be any reason to blend the exhaust ports to the RARE exhausts?
Thanks.

[78w72]

from what edelbrock says in their manual, they say do not modify the exhaust openings, i doubt you will gain any measureable power from matching them to your ram air ports.

now for max power porting, i cant say what the big porters do, i think ive read SD does do something to the ex ports, but thats beyond what the average guy can do in his garage. i'd say leave them alone unless you know what youre doing.

[West Coast GTO]

Thanks 78W72,
I have never done any port work before so I will follow your advice and leave em alone.

[78w72]

you're welcome. i thought about opening the ex ports on my heads too untill i read the manual, edelbrock claims they are a "high flow" port & says not to change it. so for my power level ~520hp, i left them alone. i say leave the mysterious porting art to guys that know what they are doing!

[Skip Fix]

You want to keep the head ports about the same unless a max effort port job. Figure even many of them that dump into 2" or larger headers have a smaller port exit.