[makilaak]

I just bought some pieces for hideaway headlights including bumper brackets to notice that those are for fixed ones... Great, yes. As I live abroad returns are impossible. I understood that you can modify them for hideaways, but I would like to know how? Does anyone have diameters for those extra supports?

[north]

Not sure what you mean. The front bumper brackets for non hideaway GTO and all LeMans are a formed single piece while the hideaway brackets are welded assembly. I guess you could make a hole in the standard brackets to allow the crank rod between the actuator and headlight door to pass.

[makilaak]

I just wondered if that supportative structure needs to be welded due to heavier light assembly? I could weld additional material, but would like to get dimensions to do that. Also I saw that there is a hole already in non-hideaway brackets, but possibly then not in right position.

[Formulajones]

I've messed with that before. All that's needed is to enlarge the holes in the standard brackets that are already there, for the actuator rod to pass through, just as North mentioned.

As far as added support, I've never found any of that to be necessary.

[steve v]

What I recall is the headlight door assembly itself will hit the standard bumper bracket as the door lowers to the open position.
The correct hideaway bumper brackets will make your life easier.

[3goats]

You can modify a standard brackets to work. They just need to move over so doors can open as OP mentioned.
I did it myself. Just slice them open and bend them to correct dimensions and fill in the hole.
I was lucky and had a hideway piece to build off and measure. etc.
These were for my race car so i didnt care about correctness i just wanted the hideaway grills to work. Turned out good and you dont really see them.
I will look for pictures and post for you if it helps.