340 swap the Duster in a time crunch! 

You gotta get moving to hit that deadline! Hope you are doing well.

that cam should be good in the 340, the 318's a okay engine & 360 a great engine, but I'd pick the 340, it's easy to add power to the 275 HP it has. can get good power from a good head porting, port matching & valve job.

You have the block out on the stand just braze it up its still a good block

Hope this is not a movie where another Mopar bites the dust..Duster don't need to bite the dust

Sorry for the problems. I have a 383hp block that has 2 1" cracks from the same thing.