'79 headers, x-pipe, and dual exhaust

[Rupesy]

I'm putting some dough together for a dual exhaust, but doesn't seem like anyone has an x-pipe and bolt on dual exhaust for a 79. Do I just need to buy the headers and then custom from there back. Maybe I'm just not looking in the right place. If someone has already done this can you post some pics?

Thanks,

[DPW928]

Haven't heard of any prefabs for the 78-79's but it would be nice.

[Landseer]

Check with Rog100.

I know for a fact that the X-pipe is a direct bolt-on for the 4.7 cars, so long as the early original cast iron manifolds are used..

If you use the better 85/6 exhaust manifold pipes, then you will need a short spacer pipe on the passenger side to mate to the X, but it still works.

I am almost positive that the 4.5 liter cars are the same as 4.7 cars regarding manifold positioning, and if they are, you have lots of options.


Then, moving back through the car, you can create your own dual system.

Magnaflow has a same side offset intermediate muffler that can be used --- I have a system posted here like that. Do a search.

[Pete R]

I switched from a 4.5 to 4.7.. with the same set up. I did end up using 85-86 4v headers that did require modification to the y pipe. I wouldn't waste my money on the dual exhaust. There would be no noticable gain over say a single pipe Borla on the 4.5.. The biggest restriction of the 4.5 is the y-pipe with cat. For some reason there is a metal plate welded in the middle of the exhaust before the cat. It removes about 1/2 the flow. I noticed it when I punched out my cat material. I cut the pipe, removed the restricting plate and that made a huge difference.

[Rupesy]

So is there much advantage going to the aftermarket headers vs the 85-86 headers? I've got the car up on jack stands, so I will have a look at the cat and plate while I'm under there.

[Landseer]

I think the headers are better and sound great.

The subject of squeezing more hp out of a tired 30 year old GT car comes up 3 times each week though.

I'd want head gaskets and bolts replaced at a minimum, and 2/6 bearing checked before thrashing one of these old girls, headers or not.

[Pete R]

If your talkin about the restricting plate I mentioned it can be seen, it's interal in the y pipe forward of the cat. I don't think either headers on a stock 4.5 are worth the hassle. They will be expensive or a pia or both. for minimal gain. Depending of your state emmission requirement the best think to do would be put on a cat bypass y-pipe. If its just a visual inspection on a 79. punch out the cat material, when you look in it you will see the little metal plate, cut the y-pipe close to where it is, cut out the restriction and reweld the pipe back together. That would be the most noticable. Every else is a lot of money for little or no gain, performance wise..though different exhaust mods will change the sound quite a bit. Most of the Hp gains with exhaust mods are at the upper end of the rpm range when the flow gets restrictive.. and how often are you running up there?

[Rupesy]

I'm looking mostly for sound and was hoping for a few extra ponys, but it isn't really my biggest priority. I would just like a little more presence when I hit the car shows. It has a nice rumble now, but would like a lot more.....I live in the back woods so car shows are always US muscle cars....I like telling them I have a V-8, but would be better if they heard it first!!

[85euro928]

Check RL. There's a set of '85 32V exhaust manifolds already ceramic coated and an X-pipe modified to fit the 16V. I believe it also includes dual SS performance cats.