r 3 combo help

Ian, you are probably going to have to adapt a Mopar 598, 598AB or 420 intake to fit your heads. It have been done before and shouldn't be too difficult. It will require redrilling the intake face mounting holes and more than likely a skim of the manifold. The cams you got off Craig will be Comp Eliminator cams and will be hard on the valve train. They will also most likefully have a lobe separation between around 112-115 degrees. The lobes will also be quite agressive, my camshaft door stop has a 0.488" lobe with [email protected]" and it's a "moderate" comp style lobe. It requires around 370-400lbs of seat pressure and around 1150lbs open. As you can imagine, not something you'll street drive!
Take the three cams down to Wade or Clive Cams and see what they can do with them for you.
As Leon suggested, go with the external pump, it's a better system and you probably have the same money tied up converting the block to a conventional wet sump system.
Have you established what the Deck Height, Bore size and main journal size is exactly as yet?