Looking at a 68 GTS.......

dart4forte said

Also, sequence numbers are stamped on the back of the block, driver side where the block and bell meet. The number is also stamped on the bell.

Here’s my original tag

View attachment 1715385520

Click to expand...

So John, yours is 383, 4 speed, built on 12/28, sequence #171005. Sequence number on block/bell best visible from top or up from underneath (with a mirror)? I assume there is a Vin tag on the dash as well?