I'm in the process of repairs / restoration on my 1980 L82.and I'm planning on replacing the exhaust system.
Since I'm going to do this, I'd like to get as much horsepower increase as I can relative to the cost/effort required.
Most bang for the buck if you will. Right now I've tentatively decided on the Magnaflow dual exhaust from Corvette
Central. I'm not planning on mods to the stock engine. I plan to remove the exhaust manifolds to at least clean them up. Undecided on whether to replace them. I'm interested in thoughts and/or experiences anyone has with this magnaflow system or alternatives. In particular relative to the following questions I have.

I believe the stock manifolds have a 2" output but the Magnaflow exhaust has 21/2" pipe after the connection to the
manifold. Is this mismatch a big deal? Is it worth going to the Magnaflow sysytem with shorty headers or maybe 2 1/2" Ramshead manifolds? Between headers and RH manifolds, I think I would prefer the RH manifolds for more of a stock look. But I've read that the HP increase would be minimal with a stock engine. So Im not sure either is worth the cost /effort. Thoughts?

It looks like the Magnaflow system has an H pipe bridge between the two exhaust sides. I want to confirm this.
Does anyone know if this is correct? If this is correct, is there any advantage to having this modded to an Xpipe crossover?

I've read that the magnaflow system is a pretty easy install. Any other systems I should consider that are as well?

Thanks in advance for your feedback

 

This is where I'm at in my decision making process, also on a 1980. Looks like the short headers that come with the CC system will not work with a large assortment of popular aftermarket heads and that's where my procrastination began on making a decision on what to do. Following for more info.

 

I used 64-65 2.5" downpies and smoothie 2.5" ramhorns and then tied it into a 2.5" 68 corvette exhaust from Corvette Central. It fit like a dream considering I'd had headers on it for decades and some fabricated exhaust attached to that. I subsequently installed a 200-4r and modified my tranny crossmember for the exhaust to pass under, so I modified my pipes to route tha-a-way. .
Hindsight being hindsight -- it would be better to install a pass-under tranny crossmember then use the 64-65 downpipes with the 2.5" ramhorns---- then you could get an exhaust installed anywhere that would be straighter and go all the way back. I can cut and weld so I modified my own.... my corvette central exhaust was fairly new so I made a couple of cuts and rewelds to go around the 200-4R .....but anyway, here is a link with part numbers and whatnot:
https://www.corvetteforum.com/forums...post1598185200.

 

I would not invest in shorty headers.

 

Thanks Carriljc. This is good info. Were you doing this on a 1980? Did you have an issue with your spark plug wires frying as mentioned by another member in the post you referenced? You had to also modify the bracket for the AC member because of the Ramhorn manifolds? I didn’t consider that.

 

gshedden
Mine is a 68. No spark plug wire issues so far. Of course you can always install all the extra shields and it's on my list of projects to bring my wires in from underneath.

I did modify the a/c bracket (mine is aftermarket), nothing difficult, a little grinding and it all fit beautifully... minor issue.

Let me get a picture of the abomination that I've made of tranny crossmember. It's all fun and games, and it's plenty strong, but I would have been better off buying an aftermarket crossmember where the exhaust passes underneath. I recommend doing that actually..... you can have a straighter exhaust and passing under makes everything much better. Let me go find the picture.

 

gshedden
Here it is. It's plenty strong since I used either 5/16" or 3/8" channel steel....which is a lot thicker than the like 1/10" box that the original is made of..... of course it looks like crap but I was able to route my exhaust quite easily.
I had fairly new exhaust from Corvette Central and I modified it to route as shown below my modified crossmember. Looking forward from the rear.

 

gshedden
Does the 1980 have the goofball 1-sided exhaust? 2 into 1, into cat, then split back out to 2? I don't think it matters if you're going to get an aftermarket crossmember

 

Do you have a pickup truck? Maybe a trailer? 4.5 hrs each way?

 

If you want the most bang for your buck from the exhaust, your search should begin and end with long-tube headers.

Anything else is just in the noise.

As @carriljc pointed out, you may need to modify or replace your crossmember to make the most of this. Plan for a manual swap while you're in there!

 

Stingr69 - so is that a new exhaust you want to sell? I may be interested. Can you give me details about it. Is it the Magnaflow system from CC?

 

Carriljc - yes my 1980 exhaust is as you described, like the picture Stringjc posted. So I don’t think I’ll havecavcrossmember issue with a system like that I’m considering. That’s why I like the CC Magnaflow system. I’ve read many users saying it goes on quite easily. Good job on your crossmember fab and thx for the picture and info

 

I will send you a PM

 

I also have a 1980 Vette. I went with long tube ceramic coated headers, 2.5 inch straight duals with an H-pipe about 9- 12 inches from headers connection. Got rid of the Cat then sent these pipes into some Flowmaster 40 series. Sounds pretty mean. One thing I would do different is besides getting ceramic headers is also wrapping them with heat tape, to get rid of heat in the engine compartment.

 

The 2.5" rams horns and Corvette Central pipes are a nice setup for engines that don't have a lot of cam overlap.......I reluctantly put a set on a 69' with one of my 357ci roller builds.....it fit perfectly and ran better than I thought.......but I still recommend long tube headers for any exhaust system if possible......the headers allow you to grow into any mods you perform in the future..........

Jebby

 

Thx to all for the info and recommendations

 

Did you have to modify the CC exhaust to mate to the 2.5” Ramhorns? Isn’t the CC exhaust made to mate to 2” manifold?

 

You may need to modify or replace your crossmember to make the most of this.

 

gshedden
I did NOT.
I used 2.5" ramhorns and 2.5" downpipes (64-65 2.5" downpipes do NOT neck down next to the manifold).
Read the thread I posted. I even included part numbers and whatnot.

 

Thx. I was wondering about the set up with Ramhorns and the CC exhaust that Jebbysan referenced in his post.