exhaust system overhaul

[jwetzel1492]

Hi everyone,
Norma Jean has a couple of exhaust leaks, and I'm looking to get it fixed up soon. I have a couple options, and I was wondering what opinions you guys could give me. She's got a 390, stock exhaust manifolds (that's where the leaks are), a brand new muffler, and an old 2" tailpipe.

Option 1: I've got a quote for $300 to pull the manifolds, resurface everything, and put her back together without the leaks. How does this sound?

Option 2: Everything in Option 1, plus: My old exhaust pipe is a 2-incher. My muffler guy says that a 390 should really have a 2 1/4", and he can put one on for $80. What kind of difference would this make? mileage? power?

Option 3: My brother (who knows quite a bit more about this than I do) says I should upgrade to dual exhausts. Could I do this with the stock manifolds, or would I need headers to make it worth it? What kind of impact (financial and performance-wise) would I be looking at?

Well, I guess that's really a bunch of questions. Look forward to hearing what you guys think.

Thanks,
Joel

[Bigblock]

I put dual exhaust on my 360. The shop went from the stock manifolds with 2 1/4" w/ turbo mufflers and dumps at the axle for $235. It sounds goods. Also, put a h-pipe in it. Hope this helps you.

[cobraF100]

Well your Brother is right.

The biggest problems with the FE's is the exhaust,it is the Best and about the Cheapest and best BANG for your $$ that you can spend on your FE.


Edited:
The Fe Exhaust was very Restrictive from the Factory.FE's need to breath on the Intake and Exhaust side.

2 1/4" Pipe would be good.Run an a set of Headers (Short or Long tubes) and you'll see "Feel" a Big improvement.

Headers can be gotton for as liitle as $150 to $315,you get what "you Pay for" and the Cheaper headers may need a little fitment work.

HedMan has a set of headers for $315 that fit good and are coated and wont rust.

A Cross Over Pipe is also a good Idea and will also help,you can use a "H" Pipe or the "X" Pipe both are good but it's been noted that the "X" Pipe is a little better.

[cobraF100]

Here are what the two look like in case you dont know..

"H" Pipe :


"X" Pipe :

[willowbilly3]

Manifold leaks has been a perenial problem of FE motors forever. Getting the top bolts out without breaking them odd is another whole discussion. Headers give a noticable improvement but aren't without their own problems. Like starter access and clearance. Many cooked starters from headers. I had Cyclones on a 360 once and it was almost a daily chore to tighten the header bolts. A couple you could only get an open end wrench on and the heads were so tiny that you just could not get them tight enough. Forget to stay on that chore and in about a week I would have a blown gasket. I am sure there are better headers than those were but that is my experience.