Dann wrote:
Not sure winabbey. From everything I’ve read they stopped the gutter stanmping early to mid 70. This is only going by my own research so don’t take it as gospel. There seems to be a lot or iregalities regarding numbers. I’ve heard they weren’t the best with protocols on stamping identification back then with wrong stamp numbers and many miss hits as can be seen in some photos over the years.
I believe the changeover from gutter to firewall was between Apr and June 1970. Not sure about the change back as 2668 is the only later car that mentions the gutter. Looks like I have to hit up some late 70S - 71S owners and see what they have.
Cars before 4/1970 YG2S4 1866 are in the gutter.
Cars after 6/1970 YG2S4 2070 are on the firewall except 2668.
edit. Updated the car numbers