Just changed the oil on my 89 6.2 1 ton and I went to Napa to get my usual 1060 filter and my trusty parts guy said they no longer are carrying the 1060. They now only sell a 1061. Whats the difference? Something about a anti drainback valve? What excactly is that? What does it do? Thanks.

An anti-drainback valve keeps the oil in the filter when the vehicle is shut off, instead of letting it drain back into the oil pan. That way, the next time you restart, the oil pump does not have to re-fill the oil filter, and you have full oil flow to the critical parts sooner.

Just changed the oil on my 89 6.2 1 ton and I went to Napa to get my usual 1060 filter and my trusty parts guy said they no longer are carrying the 1060. They now only sell a 1061. Whats the difference? Something about a anti drainback valve? What excactly is that? What does it do? Thanks.

An anti-drainback valve keeps the oil in the filter when the vehicle is shut off, instead of letting it drain back into the oil pan. That way, the next time you restart, the oil pump does not have to re-fill the oil filter, and you have full oil flow to the critical parts sooner.

Excellent post k1xv...exactly right
And bornready..This change happened a couple years ago actually...I'm kinda surprised that your store even has a 1061 on the shelf anymore to be honest.
But, if you want to see the difference without cutting the filter apart, just look in the small holes by the threads on the filter...on the 1060, you'll see orange under the holes. That's the anti-drain back. Then, look at your 1061..nothing under the holes...:)