I have a-77 suburban with 454 mk4 and th350. Th350 has Alto Red parts, b&m shift kit, adjustable vacuum modulator, governor springs, increased line pressure, just to handle 454 torque. 454 has long tube headers, eddy performer 2-0 and carter 750, RV cam and peanut port heads, msd HEI, nothing radical there. Please check out my video, there is this rattle when accelerating. There are some more videos too.