On a performance transmission setup I always recommending indexing your bellhousing to be within five thousandths of an inch of total runout. Most of the time it is the factory block that varies in tolerance, but with multiple parts stacking up together, and a slim .005 window, the tolerance can get out of spec quickly. In this video I will try to lead you through a quick process on getting you in spec.
All of my cast aluminum bellhousings are precision CNC machined to within .002 but that doesn't mean your OEM block is on center. So always check to make sure!
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