I'd like to buy a set of Summit headers but in the aplication notes it says "Must modify lower A-Arm support bracket on 1979-81 models." None of the other brands of headers say this and it has me a little worried, modifying an a-arm seems drastic. Has anyone installed these on a 79-81, is so what are they talking about, is it a PITA or no big deal.

"Must modify lower A-Arm support bracket on 1979-81 models."

It is actually not that big of a deal. There is a little bracket that runs from the backside of the lower control arm mount to the subframe itself. It is maybe 10" long. It acts like a crossbrace.

The previous owner of my car used a blue wrench (torch) to notch the top lip of the bracket (which is C shaped) to fit the headers. This applies to some other headers besides just the Summit house brand.

I have not run the Summit headers, so I'm not sure if they require a more dramatic cut or not.

It's actually pretty common to have those removed for headers. My Flowtechs didn't say to remove it but it touches so it'll come out eventually. :D

Yes, it's not a big deal, because it is a brace (that was not installed on all cars anyway), not the a-arm itself.
If you had to modify the a-arm it would be dangerous, but that isn't the case.

I had to totally remove it for the big tube hedmans I am running. Not a big deal at all.

I run Hooker Super Comps and they said to remove the bracket.

Which cars was it not installed on?? I've seen them on all of the ones I've owend.

I believe the braces were installed beginning on the 77 models on up as I don't recall them originally installed on the 70-74 cars.

None of my early SS or Z's had them up to 74 so they may have been removed...:rolleyes:

I didn't have them on my '77. The '78 and '80 do.
I wish I knew exactly what they do, since I'm going for handling on my car and I had to remove mine. I might try making a substitute after I have everything together on my car.

From what it looks like they are there to brace the A arm in case of a big hit.

I did not have them on my 77 either. The subs are the same for the most part so I would not worry about it.

The braces were installed as an attempt to stiffen the flex from the lower control arm mount to the subframe.

In extreme cornering loads GM believed this would enhance the stability and the control of the steering and increase the g's the cars would be capable of doing.

Nearly all of these are removed for the installation of headders and with all the aftermarket interlocking subframe bushings and connectors, I can't see how this would be a problem to remove.

My cheapo dynomax headers were rubbing on that brace piece (my old headers actually had the tube crushed from it) so I took it off.

had 2 1974's,, 1 1975, and 1 1976,,,,,, none of them have those braces.

I've had 2 79s and an 80, those all had them. Looks like it was added in 78. :D

I can't find the braces you guys are describing but my car has headers from the previous owner so I assume they've allready been removed. Thanks for the info, I'm putting in my order to summit.

Yeah, if the cars got headers and you cant find these, they just arent there. Have fun and remember to fire her up with open headers in the middle of the night at least once to wake up the neighbors.:)