Is this a good deal for a 340?

you are going to have to get the lower end balanced no matter what crank you go with... also a good set of .040 pistons are harder to find then say a set of .030 set... i wouldnt trust someone saying "the machining is done and its ready for assy."! you still need to check and adjust ALL clearances if you want it to live a long happy life.... i would get a virgin block and start fresh. at least a block with a crank in it. JMTC...