MKII Headers: My 2006 Summer Project

Chris Kouba


I stick by my previous scholarly comments. Phil hit the nail on the head about your repeatability. Your ability to actually manufacture sets of headers is awesome!

A little food for though for next time you're welding. I've only done small Ti parts but used a purge box instead of a cabinet. The idea is the same but visibility and dexterity are very good when weldling. It's an open-top stainless box (could be anything conductive really) which is flooded with N2 or some other inert while you weld. Still have a flow through the torch hood and you can't flail your arms or hands around while welding but it was very effective.

Actually as I sit here proofreading before I post, it dawns on me that you're probably familiar with this technique already. I'll submit the post anyway just in case though.

Keep up the good work!


Original MKIIA were 300 series stainless for sure, but can't verify 304 or 321. Because they are soo thin we opted for the 321 due to the added high temp strength. I am told that MKIV and MKIIB were inconel. Color pictures suggest it is true, as they have that spooky color. J6 would know. 304 is about double the price of mild, 321 double that of 304, and inconel double that of 321. Sainless is actually one of the easiest metals to weld. It does not oxidize easily, and holds the heat really well. 40 amps is about all it takes .

As a side note, during my research for this project I have found that there were several versions of big block headers. There is what I would call an early MKIIA style ran on the 65 cars, the later classic MKIIA that we all know, MKIIB which is a hybrid between the A and MKIV, and finally the J-car. There also appears to be differences between Shelby and Holman cars for the later MKIIA, although this just may be luck of the draw or fabrication order. I would classify ours as late Shelby MKIIA. I have seen some of the original cars (1012, 1016, 1046) that were reverted back to MKIIA level but still wear the B pipes!


Thank you my friend. I will be in DET for the month of Nov. Come up and stay a couple nights.


What a fantastic idea. The argon is heavier, and so will settle in the box forcing out the O2. I will use this if I do more collectors. Oxidation can be a problem on the inside, and it is just about impossible to set up a purge on those things.
Adam: Reminds me of when I was involved in campaigning a McLaren M1B powered by a "surplus" 302 from Jerry Titus' TransAm Mustang. We did the same as you with your CAD program by painting each branch of the headers a different color using HiTemp paint. I didn't know they had that many colors. The headerss looked a bit bazar, but it made reassembly much easier. We really found this out when we had to do a head-gasket replacement in under an hour to get the car on the grid for a race at Mid Ohio. We made the race!
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Lynn Larsen

Lynn Larsen

You probably already know this but the golden color of Mk II headers, especially the Holman-Moody cars, was not necessarily because they were made from Inconel. Inconel, that I have seen, is a much lighter hue of gold with much higher reflectivity.

I am by no means a metalurgic expert, but Lee Holman told me that the patina was the result of wiping down the headers with WD-40 and having it baked onto the header pipes repeatedly. As far as I know, it could be even both: Inconel rubbed down with WD-40.

I use an abrasive wheel to cut stainless tubing, some of the stuff we did for food and other processes had to be really good, and the really good joints were acheived with a non-reinforced abrasive wheel, a bit scary at times as we had a couple of wheels let go!, but the cut is dead square, and requires only minimal dressing before welding...which I do without filler rod most of the time. Only problem was the wheels give off a terrible smell...but in the interest of detail I use them. If you are interested I can give you a name brand off the wheel..they are reasonably cheap. Congrats again on the nice work.

Chris Kouba


Yeah, seeing it in your post was a memory jogger. We used Argon for the purge box for precisely that reason (heavier than air, stayed in the box, flooded out as you weld, maintained the inert atmosphere...).

Glad I could help!


The skill level to take this project from the drawing board to the finished project is what separates the amateur from a pro.

For me, thinking about a project like this would be unthinkable. Seeing the progress and the quality of your skill level is just great. I truly enjoy being able to watch the progress of projects like this on this site.:)

Adam, for sure........., you are one talented guy. High fives man!

Gary Kadrmas
Like others before me, your work is an art and incredible to look at. Please continue to post pictures of your progress so we wannabes can live vicariously through your efforts.
John W said:

I sent you another email ;)
Sorry, John, never got it. Please send any emails to [email protected].

Thanks all for the comments. We are not Pros, just engineers that took up fabricating as a hobby.

I think the biggest thing that holds people back is the initial outlay of money that these projects require. The tools and material to do the job right is often very expensive. It takes a real leap of faith to throw down thousands of dollars to try things you have never done before. The problem is, if you don't go whole hog you are destined to fail. We just study how others make parts, make a list of necessary tools, and go. If one process or tool does not work, look for another and try that. Don't give up because it doesn't come out quite right the first time. Our projects take a long time, but they do get done in the end.

Chris Kouba


I'll echo the other comments- those look beautiful! I'm dying to ask: did you try a purge box for the welding?

Where are you located?

GREAT work!
I haven't read all the posts in this thread, so forgive me if this was mentioned, but have you tried the Solar flux? It works great at preventing burn through, and no crazy flood boxes are needed. After cleaning out a bunch of stainless tubes with burn through with a grinder, the expensive flux is well worth it. The suggestion I was given was to get at least 70% alcohol to mix with it. Most rubbing alcohols are less than this %.
I used solar flux on the MKII collectors because I couldn't purge them, hence the suggestion for the box. I purge the tubes and the welds are perfect inside. The solar flux works so long as you weld fast. If it burns through, all you have is a mess plus oxidized material on the inside.
The only time I have had any issues with burn through is when I didn't have much practice with the stuff. Mix it thick and let it stand for a couple minutes before applying liberally with a brush. You can't bang the tubes around after it has dried or it will flake off, but as expensive as they are, I try not to bang these things around much anyway.