Product of Professional Products late Ford SB w/28oz counterwight.
Note that all of our small block Ford dampers are made to the early 1963-'69 length.
And require the use of spacers on '70 and later engines, see link below (catalog) for more info.These dampers have three sets of timing marks (60° of marks) to fit all small blocks. They also come with both 3 and 4 bolt pulley patterns.

Catalog for info here.