At first, looking at the Centerforce website it seemed that the 739 was designed for 143 tooth flywheel applications. But with somemore research It seems that they fit the same applications but the 739 is meant for higher horse power than the 675 - I emailed Brewers and their DF 10.5 inch kit is the 739 version. I think that what i'm going to order today.
On another note that magnum flywheel I need is mighty spendy.. Oh well