Does anyone know what the correct casting numbers are for the exhaust manifolds on a 1969 GTO with the standard 400CU 350HP motor. I've got several different answers on line and I can't find anything concrete. Seems everyone on line has the casting numbers mixed up for "high performance" the lower HP special order 400 and the 366HP Ram Air motors. I need the standard 400/350 HP #'s. Thanks!