Lakewood says:
Due to the manufacturing process for the bellhousing, the centerline of the bellhousing bore may not be aligned with the centerline of the crank. Lakewood recommends that you check this alignment and make any corrections if necessary. Installing a bellhousing that is not centered with the crank can result in poor shifting, clutch engagement problems, worn pilot bearing, as well as accelerated wear on the transmission bearings and gears.
Lakewood Bellhousing - Installation
Full instructions at my site:
http://www.priveye.com/images/lakewood.htm
Roscoe