You've selected the spindle with standard spindle bearing kit.

GM big bearing spindle.  For details on the the spindle bearings, use the search feature on our website, enter part number DAN706527X for the standard, or DAN706527X-HD for the HEAVY DUTY. 

It's a six bolt spindle that came on 1976-1/2 through 1991 GM six and eight lug front axles.  We also offer all the parts associated with this spindle (knuckle, bearings, hubs, spindle nuts, etc.).
 

Specifications:

OD @ inner wheel bearing:  2.000" (this is the difference between the big bearing and the small bearing spindle)
OD @ outer wheel bearing:  1.622"
OD for the seal:  2.50"
Number of bolt holes:  Six
Overall length:  6.50"