The block maybe $1500-2500 depending on how nice. Check under that surface rust for pitting also. The C4-B crank is listed as a 427 iron crank but does not have the factory
oil grooves. Figure $100 or less depending on condition and how far it's ground undersize. Nice grooved iron cranks can be had for $200 and under. 2U 390 cranks for $50 and are everywhere and very good to use. The C7-B rods are listed as 428CJ rods. But these are with the big rod bolts. There are some C7-B's that use the smaller rod bolt that came in 390's so know what your looking at. I just bought a nice set of used C7-B big bolt rods for $75. They go $100 or so needed rebuild and $195 done nicely on ebay. JMO, G.