In a previous post it was determined I have to replace the header bar. I removed everything in the way and am ready to remove the old one.

I was going to start grinding it per the Wilcox instructions and try and seperate it but in looking at it I do not see any signs of rivets to try and cut through.

I was wondering if it has been replaced before and if so how do I release the adhesive without damaging the top paint?

Maybe I am missing something here?

Thanks
Mat

 

That is a later C3 with SMC fiberglass. The headers were bonded in with epoxy or heat glue. You might be in for a bit of work. Heating may help soften it up a little. If you can get the metal off, then grind the remainder of the bonding material.

 

When did they switch over, this one is a 74 unless the front end was changed at some point?

Which is why I am a littls confused.

 

73 or 74. I am not really sure, but both have SMC front ends. 74 was the first year that the body was completely SMC.

I am assuming you are doing this because the bolts broke?

 

No the bolts broke while I was tearing it down oddly ony a couple broke.

The other side not in the photos is completely rotten, the headlight support had dropped since there was nothing left to retain it.

I managed to remove the front side will try and get the rear loose tomorrow.

I did manage to chip some glass though guess it will have to be repaired when the new bumper cover is painted. I had to heat (carefully with some propane) the rail and used a scrapper with an edge curled to seperate.

 

my 73 was bonded,
I just worked it with a heat gun and putty knife a bit at a time..mine had lots of rust so the thing fell off half way through.
Only problem is if you heat it too much you may blister the paint.

 

Where did the pics go?

72 was the last year for the bonding strip and after 72 it bonded to the surround panel.

I suppose I'll have to update the pdf file on this to reflect 1968-1972 cars only. The header removes and installs the same way fashion as described paying very close attention to not cut into the surround panel.

We cut the old headers in three sections right down the middle so you can see the knife position at all times..

Once free.. clean up the area and make perfectly sure you bond the new header in the correct position.

Post up those pictures again and lets have a look at what you have.

Willcox

 

Sorry about that I put the photos back in.

I got the thing out finally today, did end up doing some slight damage to the outer paint while flexing things.

I never want to do that again. That being said I will be ordering some new stuff in the next couple of weeks and when I get the new header bar is there anything special I should do so it will never rust out in my life time?

The ends rotten are from steel on aluminum as well as the light supports are also shot from electrolosis.

Thanks
Mat

 

Obvious signs of dissimilar metals working overtime... In the end there is nothing you can do aside from making sure everything is painted and in good shape. Even the steel bolts holding the supports to the header, if given enough time can be a source for corrosion.

When you go back with this you’ll notice there is a lip around the back side of each headlamp. If you look at the forward outer edge of the end of the header I believe you’ll also see a line. The new header should be up against the lips that run around the header and centered. When you do this it will look crooked in relation to the backside of the upper surround panel. Wait a sec.. I have a picture that will show you. I’ll see if I can get it posted.

In the top pic on the left.. you'll see the line I'm talking about. In the Z arrows you'll see the header pushed up on the lips on the backside of each opening. and also pay attention to the V in relation to the V of the surround panel.. it's not straight and trying to line this up instead of lining up the back of the headlamp openings will cause you some issues. The panel show in the pictures below is an original NOS upper GM surround panel too.. so there is no mistaking how the original part should have lined up.

One more thing.. Don't sweet it... you do have a margin for error in the supports when mounting them at the backside and GM didn't always get the headers exactly flush with the lips on the back of the openings.. You just want to make sure you don't try to use the back of the surround as a guide..

Hope this helps..

Willcox

 

 

Thanks for the help. I noticed it is referenced from the head light area. I took some measurements when I removed the old. It was about .250 in from centre of one headlight opening and about .450 on the other one.

I hope to have a list of parts in a couple of weeks.

Thanks

 

Just a quick update

Thanks to you guys and Wilcox I have the bar in and one rebuilt light assembly with new housing. The next one will go in soon.





Thanks