Their indicated airspeed to reach those negative G values were in excess of 400 knots. Not possible to get anywhere near those numbers at 210 to 230 knots. The first generation jets were also stronger and had higher VNE limits. We regularly cruised the 727 at 380 knots IAS at 16,000 feet on shuttle flights. VNE was 405. The A330 has a VNE around 330 knots and the 767 about 355.