What is this and why would it be there?

furrystump said
It wasn’t leaking before. what performance level will the motor be? Street car, stockish build. I would take “yes” for an answer and leave it be. Moderate to higher level hp, I might start looking for new block either way I wouldn’t touch the epoxy. It worked fine for stock rebuild use it for that or keep it until you can use it that way. If you can talk to the last owner and find out how longs its been that way might help you decide. If its be there for years why poke a sleeping dog?

The previous owner owned the car for 20 years. On special occasions he'd pull it out and raise cain, or take it to the drag strip. He was a Chevy guy (owned a couple of cars), but said the Dart was a car he loved to drive because it ran so well. The motor was built by the guy he bought it from.

Oldmanmopar said
On the side of the block what is the dash number. 340-1 to 340-11 ? I'll bet its a high number.

It's 340-2. 1-14-71 block and there's a large "4" cast on each side of the block.