Front Frame Rail Measurements

[sixt9stang 36]

On 5/19/2021 at 5:01 PM, aslanefe said:

I am resurrecting this old thread as it may help someone (who uses search function) in the future. I recently measured a 69 Fastback and two 69 coupe Mustangs that I believe to not have any accident damages to the frame rails etc. to find out if some of the dimensions from the diagram posted on the first post are correct. All 3 have original sheet metal. I also measured a 1970 vert but did not use the data from it as it has some sagging. Used a laser to create a datum line under the car. Laser's spec says it has accuracy of ±5/16 In. at 30 Ft. of length; as I am working on about15 Ft of car length, accuracy should be ±5/32 In. Then I created a sketch on CAD to model all 3 69s (as they have roofs and not sag a lot like the vert in time) and rotated/moved/lined all 3 up and matched 11 3/16 dimension given for rear frame rail and X-6 1/2 on all 3 cars to see how good the other dimensions on the diagram above match.

Here are my findings:

A is 12 3/4 in,

B is 12 1/8 in (or 12 3/32 in depending if you measure from the doubler in that area of the rail or the rail), 

X-6 is 6 to 6 1/4 in (varies due to very common scraping of that area of the front rails).

X-6 1/2 is 6 1/2 in,

C is 14 3/4 in

and 11 3/16 ( at the rear end of rear rails) is 11 3/16 in

So, I will be using the above dimensions to fix the sagged 70 vert.

Thanks!  I am just getting back to my car after not working on anything all winter and this will be very helpful!