TSloper

Some notes from my install...

- done on RaceRamp 10" wheel cribs (all 4 wheels)
- the fuse block must be removed to access the passenger side spark plugs and manifold bolts. Use an impact wrench to remove the positive cable nut on the side of the fuse box assembly. A couple light hits and it breaks loose without fear of cracking the plastic.
- I did not remove the coil pack cover on the passenger side. I did remove it on the driver side.
- the manifold to cat pipe nuts can be a bitch if you don't have the right socket/swivel combos (impact sockets). There is one nut on each side that really calls for a mid length socket. I unfortunately didn't have one but after many permutations of the sockets/swivels I did have I managed to get the problem children broken loose. PB Blaster is also your friend on these nuts.
- to get the cat pipes out you need to remove all of the manifold/head bolts so you can lift the manifolds and allow the cat pipe flange to clear the manifold studs. They will drop right out after that. The manifolds will also come out of the bottom without much trouble.
- if you have the dry sump system you will need to remove the oil lines going to the passenger side of the oil pan.
- unbolt the diagonal aluminum bars under the manifolds and swing them out of the way.
- remove the starter head shield. It is not necessary to remove the starter.
- the headers will slide in from the bottom without much issue. I didn't spend any more than a minute each to get the right angle
- install your primary O2 sensors BEFORE installing the headers. One additional tip... do not remove your primary O2 sensors from the manifolds if they are cold. I did this and it seized. On the second one I took a heat gun to it and it came out with little effort. The service manual also states that under 120F could make for a difficult removal.
- I purchased some DEI cool tape to cover the O2 extensions (needed for rear O2s) as well as any bare areas near the headers. I ditched the factory shielding on the passenger side O2 connectors and used the DEI tape. The factory crap was starting to dry out and crumble.
- once the headers are in install all of the bolts but leave them loose enough that you can move the header around.
- you will want to assemble the remaining exhaust pieces starting from the back and working forward. Again leave things loose.
- once you have all of the pipes fitted together start with the headers and work your way back as far a tightening the bolts and clamps.

That's about all I can remember at the moment. The fitment is excellent. I didn't get to drive it tonight but I did let everything heat up and will check the bolts in the morning.

Tim

TSloper

Test drive went well. It sounds great in sport/track mode. I definitely recommend the ARH headers.

RussM05

Good write up.

I installed ARH mid-length headers a year ago. Recently saw one of the bolts back out about 3 turns, on the driver's side. I used the ARH supplied header gaskets and bolts.

So I order new GM gaskets, ARP header bolts, and reinstalled with Loctite blue thread locker. I read the GM spec where thread lock blue is recommended. Thread locker won't work on the collector bolts because of the high heat there, but it will be fine on the bolts to the head. Should double nut the collector bolts to keep them from loosening.

TSloper

I'll be keeping an eye on the bolts. If they become a chronic problem I'll switch them out to Stage 8 or ARP.

The access to the bolts and plugs is greatly improved over the factory manifolds.