Stop in for a cup of coffee

That works with the engine number. I'm guessing now the L was probably an E. After 340 there may be an R or P and then 2750 0156, making it a '69.
I'll have to go look for the VIN on the pan rail or the bellhousing rail.

There should be a P after the 340 to signify that 340's ran on premium fuel because of the 10.5 compression...