The magnesium bellhousing is incredibly light but also quite strong. Notice those beefy ribs at the 10 and 2 o'clock positions. The rib near the starter mount (foreground) is especially important to resist cracking from the force of the high-torque starter (a weakness of many lesser bellhousings). Also note
how the bellhousing is completely machined along the faces where the transmission and starter mount. Quarter Master says its bellhousings
should have a total runout less than an incredible 0.006-inch. Here, the oil pump mount is being bolted up. The 604 crate uses an internal pump, so this mount isn't strictly necessary, but the mount also helps provide support for the bellhousing structure and weighs little since it is fabricated from aluminum, so we're installing it.