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Running gt40p heads with shorty headers that are not designed for the relocated spark plugs has lead to a few melted spark plug wires. Anybody tackle home made headers? My partner is giving it a go. Would love to see some pictures if anybody has them. Here is ours so far. Going with a tri y design. Nobody makes them for a 302 and GT40p headers. It has been tedious to say the least.





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Impressive work Sir.


  Trying to get this right on the drivers side has proven difficult. The passenger side is not as critical. We did have exhaust issues at COTA. We have been running street exhaust and it is heavy. Lost hangers on both sides. The weight of the exhaust system haning on the headers made a mess. We hope to solve both wt. And broken hanger issues with this set up. The factory hangers are not strong enough for running repeatedly over rumble strips.


  I will assume you are tig welding those headers?

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Actually, I mig weld them. I used to tig them but mig is faster and can be just as nice.


I take my time and get the ends as close to matching flush as I can (belt sander helps), carefully align and tack the tubes together, massage them to get things as close as possible then stitch around the tube. Good penetration with minimal extra material build-up. If the headers are going on a show car, I grind the welds smooth with a flapper disc then follow up with a hand-held mini-belt sander, using the back side of the belt to blend everything nicely.


Getting everything to fit properly is always a challenge, especially if one is making equal length headers! I usually get various radii U-bends to help with that. You can see in the first picture that I made a "target" for the tubes to go into at the collector end. I start with the port that's the farthest from the target and work my way to the closest. Kind of a warm-up and I find that method the easiest to build.


Once I was finished with that OHC header I split it up and sent the tubes off to a bender to get a run of tubes made. I assemble them on my jig and weld them up, then either ship them raw or get them coated. So far I've made about two dozen sets and have enough tubes for another dozen if demand is there.



I made the header in two halves for easier installation, you can see that the upper is just tubes and the lower is the collector section. I build my own collectors too; at the time three tube collectors weren't available. Being equal length makes for a pretty nice sound:


Edited by mender
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We tried everything. Ceramic leads with kevlar boots were the best but still to much heat. Since we do not have a windshield we cannot vent the engine compartment to remove some heat. When we teast and tune we remove the cowl enclosure. No issues with the leads. So......custom headers it is.



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18 minutes ago, Cam Benty said:

 we cannot vent the engine compartment to remove some heat. 




Try venting out the fenders behind the front wheels?  

We mounted one of our hood vents (actually a bilge vent louver from a speedboat ) backwards like a scoop to blow air down through the engine bay... having an angry glowing snail right next to our master cylinder was sometimes problematic :lol: 

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My tow vehicle has spark plug boots touching the headers, I used the eastwood ceramic coating on them inside and out, and haven't even melted the spark plug boot yet...  just something to think about.

Edited by Xph
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