REQUEST: Early 911 rear bumper mounting holes location

[Tomaszke]

Hi all,

I'm currently busy with an all steel backdate on my 74 Targa. And part of that is mounting the original steel LWB rear bumper. I've been looking and reading alot of backdating threads but can't find any info on where the early rear mounting holes are exactly located.

So I hope the someone here with could provide me (and future backdaters) with the needed measurements.

I did make a still of a YT video where the holes are clearly visible on which I marked the measurements needed.



And if possible maybe also pictures of frame rail with a ruler next to it are welcome.

Thanks a bunch!

[Dpmulvan]

Fit the bumper to the car, don’t rely on measurements off a longhood.

[AG81]

Do as Dpmulvan has suggested. I did. Those left and right bumper pieces, even if perfect, might be as little as 1/8" off and as much as 1/4".

[Tomaszke]

Originally Posted by AG81

Do as Dpmulvan has suggested. I did. Those left and right bumper pieces, even if perfect, might be as little as 1/8" off and as much as 1/4".

I do agree that would be the best in most situations, but as my Targa had an accident 20yrs ago and there is nothing much left to go off. I'm currently in the progress of rebuilding the rear and having some real world measurements is easier (for me atleast). And with the rear cross brace not yet welded in on mine I can insert a strengthening plate with welded nuts opposed to using rivnuts.

But in the meantime I phoned around and found a 2nd hand porsche parts dealer who had a 73 shell that I could take some measurement from. So I did a bit of a roadtrip today and got the measurements I needed.



All my measurements are metric (in mm). Keep in mind these are approximate values and could be of about 1mm, but these do seem to work for me.

A: 55mm
B: 27mm
C:195mm
D: 10mm

I had a bit of time left today and I drilled the holes in the RH side as a test. The holes are drilled 10mm, the strengthening plate has M8 nuts welded on with a 140mm distance between the centers. And you've got about 10-15mm front to back adjustment on the bumper halves themselves.

I threw the backend back together and it looks pretty close to what I expected. It all looks a bit wonky but nothing is really properly fastened. All the red/black parts are not original to the car as it a blue one



I hope this will be useful for others. Enjoy!

[Split50]

Awesome, I've been looking for these measurements for ages.

Thanks for taking the time to post them.