84 GMC K1500, 4 wheel drive engage from cab
GM 10 bolt front
I've seen 2 different spindle nut kits.
On the holed washer that fits between the 2 nuts, I've seen it with tab's and without tabs. Which one is correct for my truck?  

It should have the two nuts with a washer with holes in it and a pin on one nut, the lower one that fits into washer and washer is then keyed to spindle. (by flipping washer over you can fine tune its alignment with pin on nut) Once you get it set and locked you torque upper nut against it. You want bear a bit loose with lower nut because when you lock upper nut against it it tightens up end play a bit. It is better to error a little on the loose side on preload up there than tight side.  

Thanks for the quick reply Sno!