Slant build / pistons

What's wrong with using that block, 225 rods (easier to get and cheaper), and a stock configuration piston? Use your head. Might have to notch whatever piston you use. That would depend on the cam. You would mostllikely be near about 10 -1 CR. Would have to measure to get a closer estimate. If not enough, mill the head more, if too much, use a thicker head gasket.