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Discussion Starter · #1 ·
I switched to fuel injection (Throttle body) from a carb many years ago, and still have the original Hooker pipes that came with the car. When I converted, I was told to use the #3 pipe for the O2 sensor to sample. While that works, I think the FI would run better with the "X" collector, so to get a better sampling of the exhaust mixture.

I have seen an "X" primary pipe in pictures, would like to know more about it. Which motors it will fit, and if the pipe is designed for specific FFR models & Marks.

Can someone point me in the proper direction? Who has used this header, and your opinions?
 

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I'm using J pipes and have my O2 sensor in the PS J pipe, but have seen others install at a slight angle on the inside of the side pipes so it's out of sight. Either would give a better mix of exhaust gasses than just #3. Sorry, i know this doesn't answer your question but gives you other options
 
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Too Cheap to paint!
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Discussion Starter · #3 ·
Other idea would be to shorten the primary by 2" and create a spacer to insert with a bung?
 

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You can't put it in the collector?
 

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Discussion Starter · #6 ·
The "X" pipe I have seen is for a Coyote style motor in a FFR chassis. I am looking for the same concept for a 302/331/347, short of having to build my own.

The common thinking for the O2 sensor is 14" to 18" downstream from the exhaust port. That puts it roughly at the junction between the header and muffler sections of the standard side-pipe assembly.

If I go forwards with this project, are the flanges available, or do I have to buy an old side-pipe assembly to cut up?
 

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Discussion Starter · #7 ·
Additional thought:

Since the 351W is a wider motor, what is the difference in length between the 351 and 302 primary sections? Are there any other differences? (angle of flange on cylinder head end).
 

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I think you would be wasting your time. How far off do you think that cylinder is compared to other cylinders? If you just have to try it why not in the pipe right after the collector. There are a LOT of FFRs w/ single cylinder sampling and a LOT more in the sidepipe. They seem to run fine.
 

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Discussion Starter · #9 ·
Craig - you are correct, and I do check the plug in #3 to make sure it is running OK. I should re-do my bung installation, as it is still just a clamp-on. Buy a steel bung and weld in.

Just researching / thinking out loud to get a better sampling.
 

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Did you see my reply? Merge collector headers have all 4 header pipes merge to 1, then back to 4 to before bolting to the side pipes
 

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Discussion Starter · #11 ·
Rich - yes, but who makes them? All I can find is one for the Coyote. Otherwise, it would be custom work.
 

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They don't show them on the website, but they used to make them. There is a second company, but I can't find the link right now.:(
They have changed their website, you'll have to call to see if they still do the double collectors
 

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Discussion Starter · #13 ·

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Charter Member
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I would call GPHeaders. They state for the FF Coyote headers "Since all of our headers are built to order, your next header will be built to your vehicle’s exact specifications with options including material type, straight 4 to 4, double collector and ceramic coating". They also offer FF headers for 302W and 351W, so I'll bet they can mix the designs and you can get what you want, but you may have to wait a little longer.
 

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FFR would be cheaper (if you could get them) but Zach at GP Headers does excellent work. These are SS and made to fit my 351W powered roadster:



364406



Sean
 

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I believe George at Gas-N Pipes will also make a set. I had his pipes on my 302 (no merge collector at that time) and just ordered a set (with merge collector) for my coyote
 
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