the HYBRIDS that have been done use a Raptor 660(5v) cases while using a Raptor 700 (4v) cylinder and head
The raptor 700 cylinder has to be modified slightly to fit (the 6mm screw holes need to be offset by 2 mm.)

My recommendations for a big bore conversion would be to run a OEM RAPTOR 700 cylinder and your choice of either OEM piston or 11:1 CP. If you decide to run the OEM cylinder id recommend to mill the cylinder to increase compression and tighten up deck height