I have the vortec style Edelbrock heads and my headers dont quite match. Ive posted before for suggestions on how to fix it but I havent fixed it yet. I was just wondering if any of you have a good idea of what kind of hp loss can be expected if any? The headers are the same size and shape as the ports except they bolt up lower on the head from the bolt location, causing about 1/8 inch or so of the top of the tube in the port. Is this a serious hp loss? Any idea how much? obviously from my track times its still making plenty of power but Im just curious as to what I might gain if its even worth fixing.

I had this problem with a set of 1998 aluminum vette heads. I took the header bolt holes and elongated them so I could pull the header UP to match the location of the port. I then torqued them down. They never shifted or blew out the gaskets in 6 years. I used the factory style steel / sandwiched fabric gasket.

Good one Roger !

I was about to say have a set of headers made, but that is just too good of an idea!

Sounds good to me.....
to expand on what Roger did, you can always weld up the original opening of the holes after you enlongate them. Then you can be sure they'll never move.

I like Roger69's solution too.

To answer your question about how much HP would be lost, its hard to say, but I bet its more than just a couple. 15-20 if I had to guess, but its just a guess.

The reason I think it would cost a few HP is that exhaust gasses should be very high velocity and riding the roof of the port. At that point the 1/8" lip IMO would create a lot of turbulence and hurt flow.

Based on some of your other posts, your ET's changed pretty radically when you uncapped the exhaust - if I remember correctly. I wouldn't sweat it too much, but your exhaust system is where I would start if you are looking for more power.

Best of luck.

Roger69, I actually have already elongated them a bit but they dont stay. I guess Ill have to do some welding.

Eric68, I havent ran uncapped yet but I bet it would help. I would sure hate to find out that Im losing 15-20 hp just because I didnt spend the extra cash for the right headers, but I agree that its very likely I could be losing atleast 15hp.

I was just looking at some Hooker super comps on a friends 79z28, they fit like a glove so Im probably gonna step up to those. I havent been able to find vortec 1 3/4 headers for a 81 camaro anywhere, if any of you know a place to buy them let me know.

Here's a post from the archives with the same information.

http://www.camaros.net/cgi-bin/forum/ultimatebb.cgi?ubb=get_topic;f=4;t=004368#000006

Mine has the elongated holes and Earls gaskets. No problems.