So I'm looking to do headers on the LT1 in my 96 Camaro Z28. The only thing keeping me from doing it is how scared I am of breaking the factory exhaust manifold bolts. The rear most bolt on both the driver and passenger manifold is already broken and was when I got the car, which is causing a leak. However from what I understand, LT1 headers don't use that very last bolt in order to mount so I don't have to worry about that, but if break any of the other bolts on removal then I feel as though I'm pretty much screwed and I'll have to pull the heads, which I want to avoid at all costs.

So since the LT1 has aluminum heads, what would be the best method of minimizing the risk of breaking the bolts? Most everyone online says to just soak them in blaster and go to town, but almost every forum I find is from 10-15 maybe even 20 years ago. So I feel that method wouldn't work anymore given the car is now 27 years old and has 110,000 miles on it. Is it safe to heat up bolts on an aluminum head? It sucks because they are bolts and not studs, I'm assuming the bolts are steel but I'm not sure, so I don't know how steel fasteners react inside an aluminum head. And on top of that there is little to no room to work so I'm really counting on these bolts coming out smoothly otherwise I'm going to be screwed. Any advice? Anyone have any experience with this? People online do say they aren't supposed to be that tight so I'm hoping that is correct, but after all these years who even knows. Can I do it on a warm engine? I work at a shop so all of my tools are there and I can't do it at home so I would have to drive the car about 10 minutes there. I've seen some people say the engine has to be cold but it is just not an option for me.

 

Bolts and studs are made from the same material. Studs would just be steel on steel (steel stud and steel nut) and the nice thing about studs is you can just cut the nuts off. Studs are rarley used from the factory because they are a pain to automate.

There is always a risk of breaking bolts. If you need this car as a daily I would suggest you hold off on the headers until you have the time or the recourses to use if things go south. The back bolt not being used is news to me, I can not picture it. My SLP headers used the back bolt. If you have the headers you should be able to just look at them and tell. If there is a hole it needs a bolt in it. When I put on my headers I used a high quality Stainless bolt with a locking system to keep them from coming loose.

Aluminum and steel do not live together well. There is a process called Electrolysis that causes the metal to corrode and bind together. If there was a lot of water around the process would be quick but since the is not an area that is likely to hold water it is relatively slow. The bad part is you can have bolts that look great and be fused into a hole with no chance of coming out without drill and taping or a lot of heat. The point I am making is no one can tell you if a bolt will come out or break. You really do not know until you try.

There is a small benefit of have a steel bolt into aluminum and that is that the aluminum expands much more then the steel when heated. If you can concentrate heart on an area right around the bolt the aluminum can break the binding by expanding. Even if the bolt is glowing there is a good chance the aluminum has gotten even bigger. This takes a lot of heat since this area is used to being heated over and over again. The only reason I can think of for doing this cold would be that the binding would be brittle and it will hopefully snap. I was luck as my replacement engine was garage kept with 32K miles on it so I got lucky. No bolts broke.

While designing aluminum and steel together can cause long term issues there is very little chance it would cause an issue in the first 10 years. GM could have had the bolts ceramic coated or used studs but do they really care about 10 years from now? No they don't. Heck for less than $200 of production cost they could have built the car so it would never rust and they did not.

 

Yeah so pretty much its not that headers don't have a rear bolt, I'm not sure if you noticed but after the very last exhaust port there is two bolt holes right next to eachother. The factory manifold uses the outermost of the two holes, but most headers use the inner-most of the two holes. So if the outermost hole has a broken bolt in it, it won't matter with headers since they all use the innermost hole, at least the PaceSetters I'm planning on getting do, and most others also from what I can find. I'll just have to give it a go. The car isn't my daily driver so if something goes tragically it won't hinder me without a vehicle. I just don't have a place to work on it other than my shop at work so it would be a pain to leave it here but ill do what I have to do. We do have a torch here so I'll definitely try and heat them up before I try and get them out.

 

The blaster will break down the corrosion on anything it can get too. I like a product named Kroil better than blaster.

Ha, you are 100% right on the "back bolts" I did not notice since my car had headers but I have the original engine that came out of my car and I just looked it has both rear bolts broken off even. I guess that why I never noticed it.