Topic: 69 + 70 Rear bumper-to-bracket bolts

[AJ]

While removing rear bumpers from both my cars, I noticed a difference in bolt heads.  The bolts from my 70 (nov 69)  have a more rounded head vs. the flatter head from my other car (feb 69). 

In the photo, left to right: AMK flat style / round head / flat head

Was/is one style specific to certain year or build dates ?   

Thanks
Adrian

[jwc66k]

Knowing the Ford hardware part number would help. Try this forums library. There's a spreadsheet with 69-70 Mustang hardware listed, by Ford part number and by application (aka use). Dimensions are included so you can determine which of the three was probably factory installed. (There may also be an assembly plant difference, and a possible TSB (Technical Service Bulletin) change.)
There is a link to Ford Car Parts (aka MPC) that would list the Ford service stock number which most likely is different from the factory original.
Jim

[AJ]

Thanks Jim,   Your speadsheet gave me info that led me to AMK catalogue.  AMK shows round head style on 65-69 and flat head on 70-73. 

[jwc66k]

Thanks Jim,   Your speadsheet gave me info that led me to AMK catalogue. 

There are a lot of resources in the library and your question got you into using some of them. Knowing that "they" are there is a big step.
Jim