Just wondering about if they go in from the top, or bottem, and what to watch out for during installation. No sense in learning the same lesson multiple times. If somone can point towards some notes that someone has, it would be greatly appreciated. Thank you!
Ed

 

most headers are passenger side from top, driver side from bottom you might need to loosen motor mount and lift driver side of motor to get header in.

 

The right side header goes in from the top and the left side goes in from the bottom.

 

C5XTASY, I just finished installing them on my 99. The instructions that come with the headers are pretty good but leave a few things out. On the Passenger side you need to remove the coil packs, the spark plugs, the valve cover, and of course, the stock manifold after removing the stock H pipe from underneath. Then you must also completely loosen the starter bolts so you can move the starter enough to get the new header in. The header goes in from the top and will hang up on the starter until you move it up closer to the block. You must bolt and re-torque the starter at this time, don't wait until you have tightened the header or you can't get to one of the bolts.

The driver's side requires removal of the plugs, coil packs, AIR tube assy, and then to be safe, remove the coolant senser, and oil temp sensor along with the ground strap. Undo the serpentine belt and remove the alternator. Now you can put the header in from the bottom. From there everything should go pretty straight forward.

Make sure that you decide in advance to put anti-seize compound on the O2 sensors before you install them in the new headers. Also, decide what you will put, if anything, on the plugs when you put them back in. I would also read the instructions on www.ls1howto.com and be familier with them. They are for LG headers but pretty much cover the same thing but with pictures. Things should go pretty smooth if you take your time and double check as you go. Be sure to get the new O2 sensors in according to the directions and route the wires so they won't get burned on the headers. This seems to be where most people have problems.

 

I would also plan on replacing the heads, cam and intake manifold at the same time, which I assume would help with the header install. In addition, the installer is familiar with the LGM install, and, I undereand, the Dynatech install is supposed to be easier than the LGMs.
Why should new O2 sensors be used? Thanks!
Ed

 

both headers EASILY go in from the top. You dont have to remove the starter if you dont want to (I didnt), but you MUST remove the spark plugs because you will inevitably hit one and break it.

Instructions: http://www.secureperformanceorder.co...Instructio.pdf

Dave

 

If your O2 sensors are working OK then I see no reason to replace them. I used my original sensors, but then I only have 11,000 miles on my car. The instructions just state that it might be a good time to replace them. I have no Idea how long they last, maybe forever!