Wont spool like a set of gt35's. Depends on your goals. Those aren't well matched for a snappy 600hp setup IMO. Another member with a mild 6.0 has a set of cast 61/65's making right at 900whp and 20ishlbs. It's just overshooting your goal by quite a bit. Always going to trade snappiness/responsiveness with larger units. So you want the smallest units to meet your power goal.