IMO, unless you say Delco Rebuilt and order by specific application, you will get the generic, all cores out of one barrel, dismantled, inspected , tested to min and thats it. I have run across there differant winding, field coils and armatures , all for same application. What I did do , put the starter together with the amature with most winding, most field coils and selected the starter solenoid that did not have the teflon plunger liner and had the largest plunger. In some cases I found that the starter plunger yoke or fork , driving the bendix drive was in backwards. The other fail safe is going to a Tilton Super Starter, this is the best reduction mini starter on the market. IMO