What something is worth is in the eye of the beholder. Cleveland stuff tends to go all over the map pricewise, not as bad as some FE stuff, but it does. A block and set of 4V heads say depends on what it all needs.
Block standard bore will it stay standard? I would not buy any factory cleveland block without a sonic check and mag. Some of those blocks won't go .030" safely. You also have to be careful of stuff that sat a long time as you don't know the history. Want mag the block real good make sure no cracks including the outer water jackets. If it passes all that can see $500-$600.
4V close chamber heads would not pay more than $400 for good cores and if they are cores and will need everything (Guides, valves, convert to screw in studs, comp valve job, etc...) by time done better off getting a set of new aluminum heads. I would not re-use the factory valves.
