Anyone missing there 340 from 1970 ? Vin 1B165549

That could possible be an early 71 block.

It has 6-9-70 casting date, right around time for shut down and convert to next model year. By the time you machine the block and then build the engine it could have gone out in the end of June when the 71's were launched. You would have to see the vin on the vin pad to determine exact model year.