I'll let you know how it goes this weekend. Thanks for all your help and advice!

I went to O'Reillys Auto Parts, and they said they'd have to see the header to sell me the right gasket, it's just the stock exhaust manifold gasket I need right?

Chris Mackinlay wrote:I went to O'Reillys Auto Parts, and they said they'd have to see the header to sell me the right gasket, it's just the stock exhaust manifold gasket I need right?

Yes. They're full of s**t if they need to see the header. Just ask for a stock replacement exhaust manifold gasket. They do not need to see the header.

I went to Autozone tonight and asked for a gasket. They didn't have one, so I asked if they had one for a Sunfire, no go. The guy said it was just machined together. I told him that wasn't the case. He said I should use the one that came with the header. Would I be okay using the stock one with some gasket sealer? I hope so.

Okay, ideal install is 7.5 hours from now. Here's what I do (someone please correct me if I'm wrong):
1. Put car on ramps and cut downpipe right in front of the converter.
2. Unbolt exhaust manifold and remove from the top.
3. Bolt in the header.
4. Get under car and olt downpipe to header.
5. Fasten downpipe to the stock converter.
6. Drive to exhaust stop to have everything welded.

Is there anything I missed? I'm a little apprehensive about doing this mostly by myself.

Oh, before this I want to do the lower engine mount.
1. Jack up car.
2. Remove passenger tire.
3. Support the engine with another jack.
4. Remove stock mount.
5. Wiggle new mount into place. (How much do I tighten the new mount? (Tight, Stupidly Tight, As Tight as I can?))
6. Replace front tire.
7. Begin header install.

Again; anything I missed?

I've read both of these things are fairly easy to do, but I want the peace of mind before I start doing this.

Chris Mackinlay wrote:I went to Autozone tonight and asked for a gasket. They didn't have one, so I asked if they had one for a Sunfire, no go. The guy said it was just machined together. I told him that wasn't the case. He said I should use the one that came with the header. Would I be okay using the stock one with some gasket sealer? I hope so.

Do not use the gasket that came with the header. It is pure crap, and by using it you're just guaranteeing yourself to have to undo everything, replace it, and put it all back together again. Either order that new gasket from them and wait on the project, or use the stock gasket already there. Although I would usually never tell anyone to reuse a stock exhaust manifold gasket, it's a better bet than using the one that came with your header.

Chris Mackinlay wrote:Okay, ideal install is 7.5 hours from now. Here's what I do (someone please correct me if I'm wrong):
1. Put car on ramps and cut downpipe right in front of the converter.
2. Unbolt exhaust manifold and remove from the top.
3. Bolt in the header.
4. Get under car and olt downpipe to header.
5. Fasten downpipe to the stock converter.
6. Drive to exhaust stop to have everything welded.

Looks fine to me, don't be worried about it, all it takes is a little caution and patience, just like with anything else.

Chris Mackinlay wrote:Oh, before this I want to do the lower engine mount.
1. Jack up car.
2. Remove passenger tire.
3. Support the engine with another jack.
4. Remove stock mount.
5. Wiggle new mount into place. (How much do I tighten the new mount? (Tight, Stupidly Tight, As Tight as I can?))
6. Replace front tire.
7. Begin header install.

Excellent idea doing the mount, it will take a lot of stress off your new header. I don't have the Ecotec, but if it's anything like the 2.4L in my car, what you listed there looks exactly right. You might actually find out that you don't need to remove the passenger wheel at all. I did not, there was absolutely no reason to. As for tightening, you're gonna want it pretty damn tight, but don't go overboard.

Here's a tip that will apply to your header as well as the engine mount:
Tighten the bolts as best you can, drive it around for a couple days, and retighten all of them. This is especially important with the header because it goes through a series "heat cycles" where it heats up when you drive, and cools down when it's off. Since metal expands under heat and contracts as it cools, the bolts will become slightly loose after a couple days, and you need to retighten them. That is perfectly normal. The motor mount doesn't go through a "heat cycle" like the header, but it is under a lot of stress and definitely a lot of vibration, so it is still important to go back a couple days later and retighten them just like you did with the header.