Need help mounting bumper on 66 cuda

[Darwin]

Heres the deal. I put patch panels on the lower rear quarters and before I do the finish body work I want to fit up the rear bumper to get the right spacing between the body and bumper etc. Well I put the bumper in place with the two outside bolts, and as I tightened the bolts it drew the bumper up and before I could get the bolts tight it hit against the rear body panel. The holes in the frame are slotted, and the bolts were at their lowest point in the holes.
The bumpers were off the car when I got it. Is there some part of the bracket missing? Should I just enlarge the holes with a die grinder?
Seems pretty straight forward but I can't figure it out. Any help would be greatly appreciated.

Bob

 

[retractable]

I have a 66 Barracuda also. I have seen many bumpers with washers as spacers under the bracket to get the right fit. I think the factory did it to fit right and have the same spacing right and left. Hope that helps

 

[Darwin]

Thanks retractable, I understand the idea of shims between the bracket and frame, that is not problem.
Let me clarify, the problem I am having is more of a bumper height problem.
With the bumper in its lowest possible position, the top of the bumper is tight against the rear body panel. I need to lower the bumper about 1/4 to 1/2" for clearance along the top. The only way I see a fix is to elongate the holes in the frame, unless I am missing some part of the bracket.

 

[memike]

Give me till tomorrow morning and I will look at my 66 Valiant and see what I can come up with. They are the same.

 

[pettybludart]

You can just undo the bolts at the frame holding the brackets,loosen them off and let it drop down,then tighten.The car could have been hit in the rear or backed into something.Just a thought.

 

[Darwin]

Thanks memike, I appreciate you looking for me.
pettyblu, the car does not appear to have been hit or repaired that I can tell.