The muffler straps listed in the PET all have the same P/N (900-067-161-02) are are listed as pan head type. However, the early cars at least through 1970 used hex head bolts for the muffler straps.

In looking through my stash of muffler clamps, I found all M10 hex bolts but with a combination of lengths and head type. Some had M10 with 13 mm hex, some had M10 with 14 mm hex and many had M10 with Allen head.

I know the straps changed over the years but does anyone know what is correct for which years for the strap bolts. My important for me, what is correct for my 1970E restoration?