Assuming you've got the stamp.....you can chop it and it'll work fine. I've seen/ shot as short as a 10.5. A shorter dwell time would help with the gas face/ recoil. The type 1 system is pretty over gassed but will be dependent on the barrel/ammo/can combo. The type 3 helps a lot but can still be pretty gassy. Your op rod is fine for the type 3 but you will need a new gas tube.