FlyArmy

I am asking to find out what all is required to install long tube Speed Engineering headers with off road Y-pipe on my 2004 Silverado LT with the LQ9 engine . Is there additional items that are needed to cap off/isolate items from the exhaust or emission system to make this happen? Any information would be appreciated and thank you in advance.

Fast_six oh

Go ahead and buy some new header bolts..one or two will probably break off..the crossmember for the trans had to be lowered on mine to fit the mid pipes..i have true duals..may not have to with a y- pipe

2002_Z28_Six_Speed

iTrader: (20)

Generally manifold bolts will not work when headers are installed. The headers should come with bolts. If they do not you will need to purchase some shorter than stock.

If galling is an issue you can use an anti seize lubricant prior to install. If this issue is as big as everyone says it is I am surprised no one has tried silicon bronze bolts to prevent freezing.

53bowtie

iTrader: (6)

check out this link for some ARP studs at a good price. If you go with these make sure you leave them off until you get the headers in place.

ARP Ls1 Stainless steel header studs with locking bolts

Like mentioned above you will need to lower the trans cross member or install the passenger side header onto the Y-pipe before bolting the header to the head.

Also, it is a very tight squeeze to get the headers up past the frame and firewall. On the drivers side I found it easier to install the header from the top by removing the bolt and separating the steering shaft.

Atomic

iTrader: (42)

I did the passenger side from the top and it slid right in. I did the driver side from the bottom and it was a little more challenege, but fit fine if you can get the front of the truck up high enough to get a good angle. I didnt have to touch the shaft.

I would recommend some exhaust studs, like the ones in the post before me. But keep in mind those are not ARP even if the link says they are, they are the alper brand. I have both though and actually prefer the alper ones for what its worth.

FlyArmy

Thanks guys for the information on the installation and what to expect adding these to my truck. It should really wake the LQ9 up a little. The main question I have...Is there any exhaust emission items that need to be capped off going from the stock manifolds to the headers? I recall plugging/capping off a couple items on my 2000 Camaro with the LS1 when headers went on. I hope trucks are different. It should be a challenge for sure. Thanks again.

2002_Z28_Six_Speed

iTrader: (20)

Are you talking about having to block off the EGR with a plate on the passenger side header? You shouldn't have to do that on a 2004 year model truck. There isn't an EGR system. No plug in the manifold either.

Awwww the good old F body days!

Tex Fabnasticator

I just got through with this task recently. The headers go right on in. What made it easy for me was putting a jack under the trans and dropping out the crossmember. Then, when installing the drivers side header, lower the trans a bit, and they slide right on in. I didn't like the fit of the Y pipe. It hit my crossmember. So I went full fab on it. Installed V-bands, and custom made the rest of the tubing to cross over under the U-joint behind the crossmember. Took me quite a bit, but it works great. I had an issue with the driver's side O2 sensor being really close to the floor pan. But I did install new Bosch's, which are longer than stock. Wasn't anything a hammer could fix.
If I can figure out how to post pics, I'll show you my custom Y pipe.