Why is there such a big difference in price between the 68470 and 68471 Hedman headers?

Also, are there any headers that already have an O2 hole? Or do I need to get one welded no matter which headers I get? I'm guessing an exhaust shop would be the best place to have that done.

 

The latter have provisions for the stock AIR emissions hookups.

I'd guess that O2 sensor bungs are usually left out so the installer can choose the mounting location for the sensor. I have a set of the 68470 and the 17470 Y pipe sitting on my parts pile right now. (engine is currently at the machine shop). I'm waiting to get the motor back to determine the best location for the 02. Keep in mind you'll probably have to retrofit a heated 02 sensor in place of the stock non-heated 1 wire stock sensor.

 

Thanks for pointing that out. So do I need headers with the AIR emissions tubing, in order to stay smog legal? I'm in California.

Also where is the best place to get an O2 sensor bung welded on? An exhaust shop would be used to doing that, right? Where do I find a heated O2 sensor that will work? What's the other wire I need to run to it?

 

Yes, in CA you will ABSOLUTELY HAVE TO have the AIR stuff all hooked up right.

Whatever headers you get, make sure they have a CARB EO #. Make sure it's either prominently displayed on the headers themselves, or, that you have some form of documentation proving it. When I lived out there I used to keep a copy of the catalog page that had the EO# on it, for going through inspection.

Best place for the O2 bung is probably in the driver's side collector, as close to the engine as practical, sort of imitating the factory location. As far as "which one", it hardly matters... they're all the same, just a simple chemical process. Bosch (the inventor, owns the patent that they license to everybody) makes a "universal" one with 4 wires that works pretty good; http://www.summitracing.com/parts/bch-15730/overview/ comes with a very well-sealed splice thing to put a connector on with, you can easily gank the connector off of a stock one and splice that on it, then add a 2-wire Weatherpak for the heater. Best place to get power for the heater is the fuel pump relay.

Yes the bung is very eeeezy to add. You just take a hole saw or Unibit (I prefer a Unibit myself but w/e) to the pipe, and TIG weld it in. http://www.summitracing.com/parts/vpe-1194a

 

If you look up that part number on Jegs website, the product listing says they are NOT legal in CA. I'm not sure why since they have the AIR tubes...but I'd check with Hedman directly to see if that is in fact true or false.

I'm guessing you don't have a welder (tig or mig would be best). With that in mind I'd just dry fit your headers on the car and determine where the sensor location will be...bearing in mind clearance and wiring. As sofakingdom suggested, on the drivers side collector as close to the original location as possible would make the most sense. I'd suggest mounting it on the towards the top of the collector as much as you possibly can (keep it vertical). That way moisture that lays in your exhaust system when the car is not running won't prematurely corrode the sensor itself. Once you have your location determined and marked (sharpie should work), remove the drivers side header and take it to an exhaust shop to have them drill a hole and weld in the threaded bung.