unwanted 69 340, what would you do??

That should be an "H".

I went out to the garage and looked again at the pan rail number it is as follows. LM23P B231527. The casting date is 9.11.68 The blank space between the P and B must be a 9 but can not be read. This number decodes as.

L- Dart
M- medium
23- 2 door hardtop
P- 340 HP engine
9- 1969 model year
B- Hamtramck, Michigan
231527- vehicle sequence number

Also, on the pad below the drivers side head reads EW340P26 500539. This stamping is not good. I had to guess at some of it.

Russ