I've been told that it is likely that my header gasket is compromised (based on my description of some noise that is coming from the area - - a "pip" sound every half second or so). I guess I'll have to change the gasket. Is this tough for a no-experience guy like me to do?

The one thing I worry about is the extreme "lack-of-room" in this '66 Nova engine compartment (350 with headers). I've been told I can just loosen the bolts on the manifold a little, and slip the gasket through. Is it as easy as that sounds?

Also, should I expect that the performance has suffered as a result of this? I always thought that less back pressure was better. I've heard a little about "pressure pulse theory." I wonder if that has had an effect.

Changing header gaskets is always a chore, especially in cases where there is no room to work (which includes about 99.9% of the applications). Problem is, if you don't get all of the old gasket scrapped off it will cause your new gasket to leak.
Take all of the header bolts out, scrape the header flange and the head surface with a paint scraper, then go over both with some course sandpaper to get off all the residue. Then put the two end bolts back in without the gasket, (just barely get them started), this will line up the header. The header gaskets usually have the end bolt holes slotted so you can get the gasket in with these bolts installed. (if not, slot the holes with a utility knife) Get all the other bolts started before tightening any of them. Now tighten the bolts is several sequences, beginning with the middle ones and working outward. Be sure to use the best header gaskets you can find. I prefer the graphite with metal (wire) core. These are usually thick, so they will survive a slightly warped flange. After you have started the engine, retighten the bolts while the engine is still warm (don't burn your knuckles), then retighten them every couple thousand miles for the first few months.

"Hotrodder is NOT a nasty word"
"Too much horsepower is just enough"

Which brand header gasket is good?

I've herd people using the stock type exhaust gaskets and claim they work really good, the metal and fiber type that comes in an engine overhaul gasket set.

[ September 06, 2002: Message edited by: MHenricks ]</p>

The ones that come in the overhaul set are good gaskets, if you are using cast iron exhaust manifold. They are hard to install on headers becuays they are usually individual gaksets for each exhaust port. Best bet is good aftermarket header gasket from Victor, Fel-Pro, Mr. Gasket, etc.

If you don't mind spending a few extra bucks, try a set of the new copper gaskets, they tend to work much better. Also, don't forget to put some sealant on both sides of the copper, like high heat silicone, to help them seal off. I have been running mine for a couple of years on my shorty headers on a SBC in my '40 Buick coupe. I tightened them a couple of times after installation, check them ever so often, but have never found them to be loose. Try it, you'll like it...PACO

There is all of about an eigth of an inch between my header and the wheel well. There is greater clearance higher up vertically. Will I be able to unscrew and position the header such that I'll be able scape out all of the old gasket, and put a new gasket in?

Just to bring up an old topic:

Should I assume the gasket that is on there now is the correct size, and just match it up to a new gasket visually?

(I don't have the specs on the headers)

Also, is there any level I should torque the bolts to?

If you haven't fixed it yet, I recommend the copper gaskets. I use them and my buddies as well and never have any problems. We do not use any sealant on either side and have no leaks. If you decide to buy this type, the torque values come with the set. The good thing about them, if you do have any leaks, find where it is leaking and tighten the bolts around that port a little more and POOF - gone.

Would it be unwise to try tightening some bolts NOW (with the old gasket - - which actually appears to be pretty new), and see if the noise goes away?

Hey they are leaking anyway, I do not see what it would hurt. You said they are fairly new, so that could be the problem. I have had a the same problem in the past, what I did is for a few days, I would go and re-torque the bolts after running the motor to get it nice and hot. Did not have any problems after that. It won't hurt to try and tighten them, but do not over tighten...

[ September 12, 2002: Message edited by: 41willys ]</p>

Do you know how tight I could go? I'm a hulk of a man!, and an amateur mechanic, so there is a real danger I could screw things up! <img src="graemlins/spank.gif" border="0" alt="[spank]" />

If you draw blood than you've gone too far.

__________________
B Sinc

well, its not like I'm going to be using a machete!

hu hu, you are an amature!
you'll figure out what he means, I gar-un-tee.
A friend of mine had headders on his role back, ever couple of weeks we'd crawl under the hood and tighten them down. It would seal every time