I have a cracked left hand side exhaust manifold, I was going to have it welded but when I got to my friends house and we got a good look at it you can see that the crack goes all the way through and the manifold is effectively in 2 pieces.
SOOO...I am trying to decide if I just want to replace it with a used one off of e-bay or a scrap yard or if I want to install hedders and run a custom exhaust.
I have found Headman Hedders for $200 shipped, I am going to talk to a few shops and exhaust people to see what they say and get a few idea's on pricing.
In the mean time I am going to buy exhaust wrap and wrap them to help keep the noise down/crack from geting bigger.

So what do you guys think?
Used manifold?
Or custom exhaust?

 

Used manifold - $25 at LKQ yard near me.

 

Used manifold. Hedders will be damn hot even if wrapped and IMHO they're just too loud. I guess it just comes down to your preference, but for the extra cash you'd be spending I don't think it's worth it.

 

I've been mulling over the same question. I need new exhaust from manifolds to tail pipe. I've priced it to @ $600 not including 4 new O2's since I'll have Cat's again.

Three negative issues;

Won't add power or economy with the stock cam and more importantly stock ECU. Plus you should do a port match on intake and exhaust to see smoother flow.

May interfere with steering shaft. I've seen folks who's shorty's rubbed the shaft.

Custom exhaust from collector back which will require custom future replacements.

So there you have what I've come up with that makes the stock manifold the practical solution all the way around. Unless you are going to modify your truck and plunk down the time and money to make the headers perform a higher function it's a non-practical solution. May sound cool but they really won't scavenge like their designed to. Price wise I'll end up going over $600 to make all these changes not to mention how much time it will take to make those changes. My biggest issue with my exhaust is the connection between the Y pipe and the intermediate has rotted beyond welding up. Too thin.

 

If you go with headers, you'll likely need to shim the engine up slightly to clear the steering shaft and you may need to relocate the knock sensors as they are sometimes fouled by the headers.

The headers will make little to no difference in the exhaust amplitude as they are merely a conduit to the mufflers. If you have a sufficient muffler on it, it an be as quiet as stock.

 

Scout and PT, that was the info I was looking for, thank you guys.

Used manifold it will be then.
I knew I would not gain any power or get louder unless I changed mufflers (I do not want loud, I liked loud when I was a teenager) but the thought of dual exhaust was kinda growing on me.

 

I will have to head out to my LKQ in the future and see what they have.

 

I got a used one from Will for 40 shipped.

 

I'll tell you from tons of experience on other vehicles the lower end headers are poop in quality. They'll be a rusted up mess in less than a year and headman in particular is good for having cheesy welds on it lower end products. They do help in power in most applications but as always I don't see them doing much for a Disco unless they are followed with high flow cats and a 2.5" dual system with a balance pipe. Not sure if there are even any other options for a Disco but I always expect to pay at least $400-$500 for a decent set of headers. The painted ones suck and get really hot, ceramic coated helps but you'll pay for it and again I'm not sure if such a product even exists.

If you want to get a little boost in umph and don't want to fool with headers, try porting your stock manifolds. Its easy to do and will often yield the same gains as headers on small displacement engines. There are tons of videos and how to online and even a first timer can be really successful if he/she doesn't rush things.

The factory manifolds aren't all that restrictive anyway, its all the garbage that follows them that chokes up the exhaust system.

 

I have one form an 03', if its the same you can have it just cover shipping..