Can I use Ultra high ratio roller rockers (1.98:1) to suit ECOTEC AND L67 V6 in a VY V6?

Ultra high ratio rockers are NOT compatible with any VY V6 (supercharged and Ecotec) due to the excessive casting flash found in the pushrod bores. If you really want to run them in VY you would need to remove the heads and get them flash cleaned in order to run the 1.98 in a VY.