Header Install Process?

Fitment was a common problem with the individual flange design for headers.

unfortunately, I have no additional wisdom than what you have figured out doing the passenger side.

The tools I would be using would be pry bars, round punches and drifts, or large Phillips screwdrivers.

my first set of headers were a similar design and developed tube cracking in some of the oddest places which I attribute to the constant tension the tubing was subjected to due to the flange misalignment issue☹️

Good luck

Larry

Dear John,

       Amateur assessment and comment based on doing this more than once:

1)  The photo suggests that you have Hall Big Bore headers

2)   No surprise that they're not aligning with the exhaust port bolt holes.

3)   I think you imply that you still have a pair of junk 4V heads.

4)   Currently your good heads are on the block which is sitting in the engine bay.

      I would suggest that you compare the mis-fitment of the driver's side Big Bore header on the good heads to the 4V heads sitting in the garage.  If you're convinced that the mis-fitment is the same on both heads (it should be), then.......

      I propose you take the header and the 4V head down to a competent exhaust shop.  Explain that the header does not align with the ports and the exhaust bolt holes.  Ask whether they  can apply some oxyacetylene heat to the primaries and make them fit.  If they can do this, then be prepared with some exhaust port bolts and be prepared to remove the header wrap.  Also ask them if they can weld a rod or bar along the lower edge of the header flanges to tie them together once they're aligned properly so this problem doesn't happen again. 

        Once done, take it to the engine and confirm that all is aligned. Bolt it on with the exhaust gasket and confirm good fitment.  I have had a set that required a bit of grinding of the bar to have correct fitment.  Then you'll need to re-paint and re-wrap the headers. 

        I've done this more than once.  The additional bar welded along the lower edge of the flanges is not readily visible and is obscured by the primaries, spark plug wire ends, etc.

        Since I have adopted the welded bar, those individual and independent header flanges have *stopped* moving.

                   Warmest regards, Chuck Engles

I've also found it's easier if you use header studs rather than bolts, particularly on the driver's side.

Dear Dave,

         Yes, a good point.   Header studs are another small, but significant, aid to header installation. 

                    Warmest regards, Chuck Engles

On the Hall headers, you need to flatten the #5 pipe. It won't clear the gas tank heat shield otherwise.

Those headers weren't primarily built for the Pantera. Gary found a "boat" application for them and they were close enough.

As suggested, you may need to use studs so that as you tighten the nuts it will pull them into a better alignment but don't be surprised if you wind up having to heat them red hot, tube by tube to make them fit.

Incidentally, that heat rap has a reputation for causing the headers to rot out at an accelerated rate.

As silly as they are, the original headers (which rot out under the heat shield) and the "GTS" headers fit pretty well "out of the box".

Thanks to everyone for the information.  I was finally able to get the driver side on last night.  I used screw drivers and large clamps to pull each tube into place one by one.  I should have thought about the stud idea as that would have made this much easier.  I do like the welding idea as well and maybe its worth making measurements and having this done before I get too far along with the rebuild.

On similar topic I purchased a set of headers from PI Motorsports that looked more robust and had all the tubes welded to a single flange.  However, the passenger side collector had clearance issues with the spring.  I was surprised since these were sold as direct replacements.

Thanks,

John

#2551

...I purchased the 'Matsumoto' Headers from Hall Pantera. One Single Flange and fit perfect, a True 'Bolt-On', No Problems at all. NO Denting needed to Clear the Fuel Tank Sheild, or the Motor Mounts.

Here's a tip for those just Starting a header install...12 Point 'Header Bolts' and a 'Shorty' 12 Point 'Box-End' Wrench!! Makes 'Life Worth Living again'! Last, I'am with Doug, get rid of the Heat Wrap! It Will cause the steel to Disintegrate Faster, Especially on Stainless Headers...it Burns Out the Chromium/Nickle from the Steel/Iron! You want the Heat to Cool out to Air, Not Trapped with the Steel.

MJ

P.S. You could use 12 Point Nuts On Studs...But Then You have 2 Fasteners that Will Come Loose!!

First off from you picture, if you are using that header wrap material, there is a good chance that after a few years of driving those headers will begin to leak! I had it happen to me with a set of Hall headers. That wrap stuff is fine for race cars, but not for a vehicle that is being driven on the street.  That wrap keeps too much heat in the tubes and it will burn them out. I can't comment on the fitment issue because I have had Hall headers and now another set of headers which are the Mind Train design and never had a problem with them fitting on stock heads or CHI 2V or 3V aluminum heads.

Next time, know that it's possible to carefully shift a nearly empty fuel tank 3/4" outboard for header clearance after loosening the hold-down strap. The tank must be nearly empty or it'll be too heavy to move; a full tank weighs over 150 lb w/ 22gal. of gas @6.4 lbs/gallon. That's why IMHO the stock Pantera tank should have been on the right-hand side for better car balance, like the Mangusta.

Thanks for the information.  I ended up using the headers from PI motorsports along with stud bolts.  They still didn't fit and I ended up having to open a couple of the top holes with a die grinder.  I believe these 3V aftermarket head bolt patterns were off just enough to create the perfect storm.  4 days later I've learned many valuable lessons.

John

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