I have been looking at the dual exhaust for my 82. I like the corvette central dual setup. http://www.corvettecentralexhaust.com/performance/c3/c3_performance_dual.php

You will need the O2 sensor for sure. You really don't need the headers. If you are using the stock heads the headers won't do anything for you as far as power goes. They will look nicer. You can get rid of all the A.I.R. stuff without affecting the computer. I replaced my exhaust with a system from Mid-America. S/S pipes from manifold to mufflers and got  Magnaflow mufflers. worked great till I put in the side pipes with the new motor.

Thanks Dave. Yeah I knew with a stock setup I wasn't going to get any real perfomance advantage with the headers they just would clean things up a little. I looked at just the dual pipes from the manifolds back and may do that. I also looked at the chambered dual exhaust but not to sure about the noise level. Well, I have a few options to look at. jbs82vette2008-09-09 16:24:31

I just had "True Duals" installed on my 82; I got a transmission cross member from a 75 with the dual exhaust holes and ran the pipes that way. I also had them put in a cross over pipe (H pipe)
 I had to pass emissions so I had 2 high flow bullet cats also installed. One of the cats has the O2 bung with which I use a heated O2 sensor. I also have Hedman headers with Flowmaster 40's; emissions was way good even though I did NOT have the smog pump hooked up - I did make it LOOK like it was hooked up though in case the air nazi's looked -  they did look under the hood but didn't look undernith for cats...WTF!
  So, basicly I passed with good numbers without any part of the A.I.R system hooked up and with the high flow cats in place.

  I know they make the dual pipes for an 80-82 and I almost went that route, but seemed like a long way to go for the exhaust to get out of the car and with a lot of extra turns and resistance - so I went the route I did. The cost was much more having it custom made but I guess I'm glad I did.
  Problem is, now I am looking at Hooker's side exhaust like DaveM...... I love the sound of side pipes!
Anyway, good luck with what you finally do!

Thanks for the info. More things to think about You've done a great job with your car. I'll make a decision here in the next few weeks.

We sell a lot of '74 dual exhaust systems to put in 75 and newer cars.  You do need the crossmember with two holes, but it is a bolt in.  These systems come in 2" or 2 1/2".  They also come made to fit a 2" manifold, then pop out to 2 1/2" for the rest of the system. 

We carry heavy aluminized steel systems complete with donuts and clamps for $379.00.

Larry

Thanks Larry. I will definetly keep you in mind.